DRAM is volatile working memory; NAND flash is nonvolatile storage. DRAM holds the data and instructions that a running device is actively using and loses its contents when power is removed. NAND flash stores files, applications and operating-system data without continuous power, so it is used in SSDs, USB flash drives and memory cards.
They are not competing versions of the same component. A computer can use both at once: DRAM runs active workloads, while an SSD stores data in NAND. Some SSDs also include a smaller DRAM chip to cache the drive’s mapping information, but that cache is not where your files are permanently kept.
As an Amazon Associate I earn from qualifying purchases.
DRAM and NAND flash at a glance
| Characteristic | DRAM | NAND flash |
|---|---|---|
| Power behavior | Volatile: contents disappear when power is removed and the cells require periodic refresh while powered. | Nonvolatile: stored information remains when power is removed. |
| Primary role | Working memory for active programs, data and instructions. | Persistent storage for files, applications and system data. |
| Typical products | Desktop and laptop RAM, mobile LPDDR, graphics memory and high-bandwidth memory. | SSDs, USB flash drives, SD cards and microSD cards. |
| What a buyer checks | Supported memory generation, module form factor, capacity and rated speed. | Interface, form factor, capacity, workload suitability and the complete drive’s specifications. |
There is no universal winner. The right technology depends on the job: active computation favors DRAM, while durable storage favors NAND flash.
Free tools Windows power users keep installed
One-click scans. No signup required.
What DRAM is and why systems need it
Dynamic random-access memory is temporary workspace
DRAM stands for dynamic random-access memory. When you open a program, edit a document or switch between browser tabs, the operating system places the information it needs in working memory. The processor can then access that active information without repeatedly retrieving it from a storage device.
#1 Best Overall
- MEET THE NEXT GEN: Consider this a cheat code; Our Samsung 990 PRO Gen4 SSD helps you reach near max performance with lightning-fast speeds; Whether you’re a hardcore gamer or a tech guru, you’ll get power efficiency built for the final boss
- REACH THE NEXT LEVEL: Gen4 steps up with faster transfer speeds and high-performance bandwidth; With a more than 55% improvement in random performance compared to 980 PRO, it’s here for heavy computing and faster loading
- THE FASTEST SSD FROM THE WORLD'S FLASH MEMORY BRAND: The speed you need for any occasion; With read and write speeds up to 7450/6900 MB/s you’ll reach near max performance of PCIe 4.0 powering through for any use
- PLAY WITHOUT LIMITS: Give yourself some space with storage capacities from 1TB to 4TB; Sync all your saves and reign supreme in gaming, video editing, data analysis and more
- IT’S A POWER MOVE: Save the power for your performance; Get power efficiency all while experiencing up to 50% improved performance per watt over the 980 PRO; It makes every move more effective with less consumption
A conventional DRAM cell uses a transistor and a capacitor. The capacitor’s electrical charge represents the stored bit, but the charge gradually leaks. Memory circuitry therefore refreshes the cells repeatedly while the system is powered. If power stops, the charge is no longer maintained and the contents are lost.
DRAM is a type of RAM, not a separate alternative to RAM
RAM is the broad category of random-access memory. DRAM is one implementation of it; static RAM, or SRAM, is another. SRAM uses a different cell design and is commonly used for small, very fast caches inside processors. When a computer specification says it has system RAM, that memory is usually DRAM, such as a DDR-generation desktop module or LPDDR in a phone.
DRAM families serve different devices
Manufacturers produce several DRAM families for different electrical, physical and bandwidth requirements. DDR is common in desktop and server memory, LPDDR targets mobile devices, GDDR is designed for graphics processors, and HBM provides very wide bandwidth for graphics and compute accelerators. These names describe families and interfaces; they do not make the memory nonvolatile.
PC Slower Than It Used to Be?
A free scan shows the junk files, broken settings and background clutter dragging Windows down - then fixes them in one click.Free scan · Windows 10 & 11Crashes, No Sound, or Screen Glitches?
Random freezes, missing sound and display glitches usually trace back to one bad driver. Find and replace yours safely.Free scan · under a minuteWhat happens when DRAM fills up?
When available DRAM becomes scarce, an operating system can move less-active information to storage and bring it back when needed. This paging or swapping allows a workload to continue, but it uses the storage device for a job that system memory normally handles. The practical lesson is to buy enough compatible DRAM for the applications you actually run rather than assuming storage capacity can replace working memory.
What NAND flash is and how it stores data
NAND is nonvolatile flash memory
NAND flash records information in memory cells that retain their state without an external power source. That is why a file remains on an SSD after shutdown and why a photo card can be removed from a camera without losing its contents. NAND is a memory technology, not the name of a finished drive.
In a storage product, NAND cells are arranged into pages and larger blocks. A controller and firmware decide where data is placed, translate logical addresses used by the operating system into physical NAND locations, correct errors and manage the blocks over time. The resulting behavior belongs to the entire product, not just to the cells.
Why pages and blocks matter
Pages are the smaller units used for reading and writing data, while blocks group pages for management operations. Flash storage cannot be treated exactly like a blank sheet on which every byte is overwritten independently. The controller must track valid and obsolete pages, reclaim space and coordinate block operations. That is why free space, write patterns and firmware behavior can affect an SSD’s response during sustained work.
Why an SSD is more than NAND chips
An SSD combines NAND packages with a controller, firmware, a host interface and usually some form of temporary buffer. The interface may be SATA or NVMe, and the physical form factor can vary. Wear leveling spreads writes across available cells, while error-correction mechanisms help the controller recover data as cells age. These functions mean two drives using similar NAND can behave differently under the same workload.
Flash products beyond SSDs
USB flash drives, SD cards and microSD cards also commonly use NAND. Their compact controllers and interfaces are designed for removable use, cameras, phones or general file transfer rather than necessarily matching an internal SSD’s behavior. A card’s label identifies a finished product with its own controller and firmware; it does not provide a universal speed or endurance guarantee for every device using the same cell type.
NAND cell types trade density for other characteristics
The number of bits stored in each NAND cell affects density and the way the product is designed. Micron’s broad classifications are:
Rank #2
- Ideal for high speed, low power storage
- Gen 4x4 NVMe PCle performance
- Up to 6,000MB/s read, 4,000MB/s write
- Includes Acronis cloning software
- 5-year limited warranty
| Type | Bits per cell | Typical positioning |
|---|---|---|
| SLC | 1 | Lower density and commonly associated with demanding performance or endurance requirements. |
| MLC | 2 | Higher density than SLC, with a different performance and endurance balance. |
| TLC | 3 | Dense storage used broadly in consumer and mass-storage products. |
| QLC | 4 | Higher density for mass storage, with trade-offs that depend on the complete product. |
These are technology descriptions, not promises that every SLC product is faster or every QLC product is slower in every situation. Controller design, firmware, workload, available spare area and the drive’s cache strategy all influence actual results. A cell-bit label alone cannot establish a drive’s speed, endurance or useful life.
Higher bits per cell can make more capacity available from a given amount of silicon, but storing more states in each cell also changes how the controller programs, reads and corrects the cells. The useful comparison is therefore between complete, specified products. Look for the manufacturer’s workload and endurance information for the exact model instead of treating SLC, MLC, TLC or QLC as a ranking that applies in every case.
DRAM and NAND do different jobs in one computer
During normal work
The processor runs instructions and manipulates active data in DRAM. The operating system and applications remain stored in NAND-based storage when they are not actively being used. When you launch an application, the system reads its files from the SSD into DRAM. Closing the application releases that working space, while the application remains on the SSD.
For example, opening a large project can involve several transfers: program files and project data begin in NAND, the operating system loads frequently used portions into DRAM, and the processor works on those in-memory copies. Saving sends changed information back through the storage stack to NAND. Both components participate, but neither substitutes for the other.
During sleep, shutdown and power loss
Because DRAM is volatile, an ordinary shutdown clears its contents. NAND retains stored data through a shutdown or a disconnected battery. Sleep and hibernation behavior varies by operating system: a sleep state may keep DRAM powered, while hibernation writes a memory image to storage before powering down. The distinction remains the same—DRAM needs maintained power, NAND does not.
A power-loss-safe design should not be confused with ordinary retention. DRAM can preserve a running session only while the platform supplies the power and refresh it requires. NAND’s nonvolatile property protects stored bits from an ordinary loss of power, but it does not protect against a damaged device, controller failure, corrupted files or deletion.
Why an SSD can contain DRAM
An SSD controller maintains a mapping table that records where the operating system’s logical addresses are located in NAND. A drive may keep part of this metadata in DRAM so the controller can consult it quickly. The DRAM is therefore a cache for internal management information, not the permanent home of the user’s documents or photos.
This arrangement explains why a drive can be advertised as an SSD with DRAM without being a system-memory product. The drive still uses NAND for persistent capacity. The small DRAM component supports address translation and other controller work, while the NAND packages hold the actual data.
If an SSD has little or no dedicated DRAM, its controller can use other techniques, such as keeping more metadata in NAND or borrowing a portion of the host system’s memory where supported. Those designs can be perfectly suitable for some workloads, but their behavior depends on the specific model and firmware. Do not infer that an SSD is DRAM-based simply because its specification mentions a DRAM cache.
Do these 3 things before closing this tab:
1Scan for outdated or missing drivers - takes under a minute2Repair Windows errors before they cause bigger problems3Fix the driver behind crashes, sound loss and screen glitchesHow to compare them without misleading speed claims
DRAM and NAND are used in different roles, so a single “which is faster?” answer is not meaningful. A DRAM module and an NVMe SSD do not perform the same operation or connect through the same interface. Product-level comparisons should use matched measurements and the workload that matters to you.
Rank #3
- SPEED UP PROJECTS. Launch creator applications fast with uncompromising PCIe 4.0 read speeds up to 7,100MB/s,[2] (1TB and 2TB[1] models) and write speeds up to 6,700MB/s[2] (1TB[1]-4TB[1] models).
- CREATE AND STORE MORE. Make more room for your 4K videos and high-resolution images with capacities from 500GB[1] up to 4TB[1] on M.2 2280 built with our trusted 8th generation SANDISK BiCS QLC 3D CBA NAND.
- IT GOES WHERE YOU GO. With an all-new power efficient design, your drive delivers high performance with low power, giving you more time to be productive while on the go.
- UNCOMPROMISED RELIABILITY. With up to 1,200 TBW[3] (4TB[1] model) endurance rating, your drive is designed for creators.
- KEEP YOUR DRIVE UPDATED. Monitor your SSD’s performance and check for updates with the downloadable SANDISK Dashboard application.[5]
- Retention: choose DRAM for temporary working data and NAND for information that must survive a power-off event.
- Role: DRAM supports active computation; NAND provides persistent capacity.
- Access pattern: system memory serves frequent active reads and writes, while storage handles file transfers and operating-system requests through its controller and interface.
- Capacity and density: NAND products are built for large persistent capacities; DRAM capacity is selected to keep the applications you run active without excessive paging.
- Finished-product behavior: an SSD’s interface, controller, firmware, cache and NAND type all matter. A NAND cell category by itself is not a benchmark.
Claims such as “DRAM is a fixed number of times faster than NAND” are not useful without specifying the products, interfaces, queue depths, transfer sizes and workload. The technical distinction is about function and retention, not one universal speed ratio.
Why interface labels matter
For storage, SATA and NVMe identify different host-interface categories, and the connector or physical form factor determines whether a drive can be installed. For memory, DDR generations and module types determine platform compatibility. These labels should be compared within their own product class, not placed on one shared speed scale.
What to check when buying or upgrading DRAM
Confirm compatibility first
Before buying a memory module, check the motherboard or device documentation for the supported DDR generation, maximum capacity, slot or soldered-memory arrangement and module form factor. Desktop DIMMs, laptop SO-DIMMs and soldered LPDDR are not interchangeable simply because they are all DRAM.
The Tool Desk
Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →Also verify how many slots are available and whether the platform has limits on the number or arrangement of modules. A module that physically fits may still be the wrong generation or unsupported configuration. Use the system maker’s specifications as the starting point rather than relying only on a retailer’s category label.
Match capacity to your workload
More DRAM can let you keep more applications, browser tabs or large datasets active before the operating system moves data to storage. Capacity should follow your actual workload rather than a generic claim that one generation is always better. A supported module with the right form factor is more valuable than a faster-rated part that the system cannot run at its advertised setting.
Understand rated speed in context
Rated memory speed is subject to the processor, motherboard, firmware and module configuration. Check the platform’s supported settings and whether installing multiple modules changes the attainable rate. The rating describes the module’s specification; it does not guarantee the same result in every system.
Do not confuse graphics memory with system memory
GDDR and HBM are DRAM families intended for graphics or compute accelerators, while DDR and LPDDR commonly serve general system memory roles. They are all DRAM, but their packages, interfaces and platform requirements differ. A specification naming one family is not an invitation to substitute another.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
What to check when choosing NAND-based storage
Start with interface and form factor
Verify whether the device accepts a SATA drive, an NVMe drive or a removable card, and confirm the required physical size and connector. An NVMe drive cannot be installed in a slot intended only for SATA, even if both products are described as SSDs.
Match capacity and workload
Capacity should cover the operating system, applications, personal files and working free space. Consider whether your use is mostly light document storage, sustained video or other long transfers, frequent scratch-file writes, or a system drive serving many simultaneous requests. The controller, firmware and NAND configuration determine how a drive behaves after its temporary cache fills.
A drive used mainly for occasional documents has a different workload from one receiving continuous large writes. For the latter, examine the exact model’s sustained-workload information rather than relying on a short burst specification. The same principle applies to removable media used for cameras, phones or frequent file transfers.
Rank #4
- HUGE SPEED BOOST: Get random read/write speeds that are 40%/55% faster than 980 PRO; Experience up to 1400K/1550K IOPS, while sequential read/write speeds up to 7,450/6,900 MB/s reach near the max performance of PCIe 4.0*
- BREAKTHROUGH POWER EFFICIENCY: Use less power and get more performance; Enjoy up to 50% improved performance per watt over 980 PRO, plus optimal power efficiency with max PCIe 4.0 performance**
- SMART THERMAL CONTROL: Samsung's own nickel-coated controller delivers effective thermal control; With its slim size, 990 PRO is a perfect fit for desktops and laptops that meet the PCI-SIG D8 standard***
- THE CHAMPION MAKER: Up to 65% improvement in random performance enables faster loads for an ultimate gaming experience on PS5 and DirectStorage PC games****
- SAMSUNG MAGICIAN SOFTWARE: Get the most out of your SSD with Samsung Magician's advanced yet intuitive optimization tools; Monitor drive health, protect valuable data, and receive important updates for your 990 PRO
Read the complete specification
Look for the drive’s stated interface, form factor, capacity, workload ratings and any endurance information supplied for that exact model. Treat SLC, MLC, TLC or QLC as one design attribute rather than a complete performance verdict. A removable USB drive or memory card also includes a controller and should be judged as a finished product.
Recommended Free Tools
Keep backups independent of the drive
NAND is nonvolatile, but nonvolatile does not mean indestructible. A controller failure, physical damage, file-system corruption or accidental deletion can still make data unavailable. Maintain a separate backup of important files rather than treating the retention property of flash memory as a backup plan.
Common misconceptions, corrected
“DRAM and RAM are two competing things.”
DRAM is one kind of RAM. SRAM is another. In ordinary desktop and laptop specifications, the main system memory is generally DRAM.
“An SSD is DRAM.”
An SSD is a storage device whose main persistent medium is NAND flash. Some SSDs add DRAM for mapping-table or other internal metadata caching, but the user’s stored files remain in NAND.
“NAND and SSD mean the same thing.”
NAND names the flash-memory technology. An SSD is a complete product built from NAND, a controller, firmware, an interface and supporting components. USB flash drives and SD or microSD cards can also use NAND without being SSDs.
Quick wins for a faster PC:
Repair Windows errors before they cause bigger problemsFix Now →Scan for outdated or missing drivers - takes under a minuteDriver Scan →Clear out junk files and repair common Windows errorsFree Scan →“NAND has one fixed speed and endurance level.”
NAND cell density, controller behavior, firmware, spare area and workload all affect the finished product. SLC, MLC, TLC and QLC labels describe bits per cell, not a universal promise about every drive.
“Nonvolatile means my files are automatically backed up.”
Retention through a power-off event is only one property. It does not prevent deletion, corruption, hardware damage or a controller fault. Important data still needs an independent backup.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.A practical decision framework
- Ask whether the data must survive power loss. If it is active workspace, you are considering DRAM; if it is persistent data, you are considering NAND-based storage.
- Identify the device role. For system memory, check DRAM generation, form factor and platform limits. For storage, check the host interface, physical fit and complete drive specifications.
- Describe the workload. Frequent active multitasking points to adequate DRAM capacity. Large files, application libraries and operating-system storage point to NAND capacity and an appropriate SSD or flash-card design.
- Compare like with like. Use product-level measurements from the same class of device and workload. Do not compare a memory-module rating directly with a storage-drive rating.
- Check the whole product. For SSDs and removable media, consider controller, firmware, interface, cache behavior, NAND configuration and stated workload ratings together.
- Plan for failure. Keep independent backups of important NAND-stored data and avoid buying unsupported DRAM that cannot operate in your system.
Frequently asked questions
Is DRAM the same as NAND?
No. DRAM is volatile working memory that needs refresh while powered. NAND flash is nonvolatile memory used for persistent storage.
Does NAND keep data when the power is off?
Yes. NAND is designed to retain stored information without continuous external power. That does not make a flash device immune to physical failure, corruption or accidental deletion.
Why does an SSD have DRAM?
Some SSDs use DRAM to cache the mapping table that connects the operating system’s logical addresses with physical NAND locations. It is controller metadata cache, not the main storage location for your files.
Best Value
- This product has been replaced by our latest generation. Please search for the SANDISK Optimus GX 7100 NVMe SSD
- HIGH-OCTANE GAMING. Experience speeds up to 7,250MB/s read and 6,900MB/s write (1-2TB models), with up to 35% faster performance than previous generation.
- PURPOSE-BUILT. Designed for serious on-the-go gamers, with a PCIe Gen4 interface and SANDISK’s next generation TLC 3D NAND.
- MORE TIME TO CLEAR THAT CHECKPOINT. Built with laptops and handheld gaming devices in mind, with up to 100% more power efficiency over the previous generation.
- DO MORE WITH DASHBOARD. Ensure your drive is optimized for prime performance with the downloadable WD_BLACK Dashboard (Windows only).
Can I use an SSD instead of RAM?
No. An SSD provides persistent storage, while DRAM provides the fast working space used by active programs and data. Operating systems may page to storage when DRAM is scarce, but that is not a direct replacement for adequate system memory.
Is an SSD with no DRAM defective?
Not necessarily. A drive without dedicated DRAM may keep more metadata in NAND or use host memory where supported. Suitability depends on the model, firmware and workload, so evaluate the complete specification.
Which NAND type should I choose: SLC, MLC, TLC or QLC?
The labels indicate one, two, three or four bits per cell, respectively. They describe density and design trade-offs, not a universal ranking. Choose based on the exact product’s interface, capacity, workload information and endurance specifications.
Quick wins for a faster PC:
Scan for outdated or missing drivers - takes under a minuteDriver Scan →Clear out junk files and repair common Windows errorsFree Scan →Will NAND data last forever without power?
NAND is nonvolatile, but “nonvolatile” does not promise permanence under every condition. Device age, physical damage, controller problems and file-system issues can still make data unavailable. Keep separate backups.
Can any DDR module fit any computer?
No. Check the supported DDR generation, capacity limits, slot or soldered arrangement and module form factor. Desktop DIMMs, laptop SO-DIMMs and soldered LPDDR require different platform support.
The bottom line
DRAM is fast, temporary working memory that must be refreshed and loses its contents without power. NAND flash is persistent memory used to store data in SSDs and removable flash products. An SSD may contain both: NAND holds the files, while a smaller DRAM cache can help the controller manage its address mapping. For a purchase, focus on compatibility and workload—supported DRAM specifications for memory upgrades, and interface, form factor, capacity and full-drive behavior for NAND storage.
Frequently Asked Questions
What is the simplest difference between DRAM and NAND flash?
DRAM is volatile working memory for active programs and data. NAND flash is nonvolatile storage that keeps information when power is removed.
PC Slower Than It Used to Be?
A free scan shows the junk files, broken settings and background clutter dragging Windows down - then fixes them in one click.Free scan · Windows 10 & 11Crashes, No Sound, or Screen Glitches?
Random freezes, missing sound and display glitches usually trace back to one bad driver. Find and replace yours safely.Free scan · under a minuteWhy can one SSD contain both NAND and DRAM?
NAND stores the user’s persistent data. A smaller DRAM component may cache the SSD controller’s logical-to-physical mapping information and other metadata.
Does a higher-bit NAND cell automatically mean a slower or less reliable drive?
No. SLC, MLC, TLC and QLC describe bits per cell. Controller design, firmware, spare area, workload and the complete product specification also determine behavior.
What should I verify before buying a RAM module?
Check the supported DDR generation, maximum capacity, slot or soldered-memory arrangement, module form factor and platform-supported speed.
What should I verify before buying an SSD?
Confirm the interface, physical form factor, capacity and workload fit, then review the exact model’s controller, NAND configuration, cache behavior and stated endurance or workload information.
Does nonvolatile NAND eliminate the need for backups?
No. Power-off retention does not protect against deletion, corruption, physical damage or controller failure. Keep important data on an independent backup.
The Bottom Line
DRAM is volatile workspace; NAND flash is persistent storage. Systems commonly use both, and an SSD may add DRAM for its internal mapping cache. Choose compatible DRAM for active workloads and evaluate NAND storage as a complete product—interface, form factor, capacity, controller, firmware and workload—not by a cell-type label alone.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
