Recommended Free Tools
iTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
There is no universal BIOS switch that makes an NVMe SSD run at full speed. First check whether the drive is installed in a slot that supports its PCIe generation and lane width, then review the motherboard’s lane-sharing notes and any model-specific BIOS lane setting. A BIOS option may redistribute lanes rather than add bandwidth.
What “half speed” actually means
An SSD’s advertised sequential read or write rate is not the same thing as the PCIe link it negotiated with the system. A benchmark result can also vary with the test and workload, so a result that looks roughly half of an advertised figure does not, by itself, identify a BIOS problem.
Check the measurement tool’s reported link generation and width, if available, and compare those with both the drive’s specifications and the exact M.2 socket’s capabilities. M.2 describes a form factor, not a guarantee of a particular protocol, PCIe generation, or lane count. PCI-SIG’s reference material describes M.2 Socket 3 as supporting up to four PCIe lanes, while configurations can use fewer: PCI-SIG’s M.2 reference.
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1Scan for outdated or missing drivers - takes under a minute2Repair Windows errors before they cause bigger problems3Fix the driver behind crashes, sound loss and screen glitchesCheck the motherboard slot and lane-sharing table
Confirm what the occupied socket supports
Find the motherboard’s exact model and consult its manual. For the M.2 socket in use, note its maximum PCIe generation, lane width, supported drive types, physical length, and any CPU-dependent restrictions. A drive capable of a newer or wider link cannot exceed what that socket and processor provide.
#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
Look for shared lanes and disabled ports
Use the manual’s lane-sharing table to see whether that M.2 socket shares resources with another M.2 socket, an expansion slot, a SATA port, or another controller. The result depends on the board and sometimes the CPU installed. ASRock documents that M.2 sockets can share lanes with PCIe slots or SATA ports; MSI also describes board-specific lane sharing and BIOS lane modes. These are examples of why the exact board manual matters, not universal settings: MSI’s PCIe lane-configuration guidance and ASRock’s M.2 FAQ.
When a BIOS lane setting is relevant
Only inspect BIOS options after identifying the motherboard and the socket’s documented behavior. Menu names and effects vary by board. A lane mode or bifurcation option can divide available lanes among devices; it may be necessary for a particular configuration, but it does not create additional lanes or necessarily improve SSD speed. MSI’s examples are specific to supported board families, so do not apply their menu path or setting to a different model.
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
If the manual identifies a relevant setting, follow the vendor’s instructions for that model and understand what other devices may be affected before changing it. Avoid changing unrelated PCIe settings based on a generic online recipe.
Work through the checks in order
- Identify the system: record the motherboard model, CPU model, SSD model, M.2 socket used, BIOS version, operating system, and the tool and result behind the “half speed” reading.
- Verify the socket: use the motherboard manual to confirm the slot’s PCIe generation, lane width, supported drive types, and CPU caveats.
- Check resource sharing: review the board’s lane map for any slot, port, or controller that shares bandwidth or becomes unavailable when that M.2 socket is populated.
- Compare the negotiated link: compare the reported PCIe generation and lane width with the SSD and socket specifications. A mismatch helps narrow the investigation but does not alone establish its cause.
- Investigate remaining mismatches: check that the drive is seated correctly, review applicable firmware notes, verify CPU compatibility, and consult support for the exact motherboard-and-drive configuration.
When replacing the SSD makes sense
Consider replacement if the drive is faulty or you want an upgrade for other reasons—not simply because a benchmark looks low. Before choosing a replacement, match its PCIe generation, maximum lane width, M.2 physical length, and protocol to the motherboard socket and CPU. A new drive cannot make a host slot supply more lanes.
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]
For example, PCI-SIG lists the ADATA SM2P41C8 as a PCIe 4.0, x4, M.2 2280 NVMe SSD. That illustrates why “M.2” alone is not enough to establish compatibility; confirm the specifications for your own drive and board: PCI-SIG’s ADATA listing.
Quick Recap
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).
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
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.
