New Samsung 4TB drive is slow - Page 1
Forum section: electronics / general

author: raptor1956
author_rank: Frequent Contributor
timestamp: August 21, 2025, 04:04:03 am
content: Just picked up a 4TB Sansung 990 Evo Plus and running Samsung's Magician software to benchmark it's performance, which is rated at 7250MB/s (presumably read speed), but I'm getting about half that -- here's what Magician reports:app 3700 MB/s Seq Read, 3350 MB/s Seq Write, 870500 IOPS Random Read, 762000 IOPS Random WriteNow here's what has me a bit sus...From System Details within Magician it indicates the Motherboard was made by Shenzhen Meigao Electronic Equipment Co., Ltdthe BIOS is American Megatrendsthe memory is listed as Micron TechnologySince when has Micron been making flash for Samsung?Am I missing something?Brian

author: amyk
author_rank: Super Contributor
timestamp: August 21, 2025, 04:14:19 am
content: I believe that's the RAM in your computer, not the SSD itself. However, fake Samsung SSDs have been seen, so where did you buy it?https://old.reddit.com/r/pcmasterrace/comments/1kwpxfe/bought_fake_990_evo_plus_4tb_from_bestbuy_confirm/(Don't ask me why they thought it necessary to put that in an application for monitoring an SSD.)

author: raptor1956
author_rank: Frequent Contributor
timestamp: August 21, 2025, 06:38:15 am
content: Yeah it looks like the Magician was reporting the motherboard of the PC, not the SSD itself. Though a closer look is odd as it reports in one place that the memory is configured as:Slot 1 -- 32767MB, SODIMM, MicronSlot 2 -- 32767MB, SODIMM, Micronwhich total 64GB but the PC has 96GB and later Magician reports the total physical memory is 93.684GB (96GB).And this brings me back to the other SSD, the one that came preinstalled, a 2TB unit from Crucial and it's quite a bit faster than the 990 Evo PlusSSD Seq Read Seq Write Random Read Random WritePreinstalled 4826 MB/s 4703 MB/s 437011 IOPS 370117 IOPS990 Evo + 3676 MB/s 3330 MB/s 870117 IOPS 764160 IOPSSo, there's all kinds of weirdness going on with the Samsung being much slower for sequential reads and writes but twice as fast with random reads and writes.Brian

author: Berni
author_rank: Super Contributor
timestamp: August 21, 2025, 06:52:30 am
content: What type of PCIe bus did you plug your SSD into?You can only get these sort of speeds on a PCIe 4.0 4x bus or higher.

author: darkspr1te
author_rank: Frequent Contributor
timestamp: August 21, 2025, 07:03:17 am
content: With modern motherboards there are often a few gotcha's.Some boards will share PCi-e bus in some ways, a example is my Asus ROG crosshair, the primary NVME boot drive shares it's lanes with the gfx card, if i put a super fast ssd in that slot it will always be slower than when i fit it to a card and attach to another pcie slot then both the nvme and gfx work as expected.another board i have has 4 nvme slots but slot 1/3 and 2/4 share lanes, so the only way to get max out is use only 1 & 4 slots.bios options also come into play here, on my second board the is a option allow lane sharing off/on and if on then it will always halve the lanes to each pcie device unless the devices requests them and I have yet to find a device that supports this.just a few hints at would could affect your results.darkspr1te

author: iMo
author_rank: Super Contributor
timestamp: August 21, 2025, 07:10:43 am
content: Samsung is using Samsung memories only, afaik, and they have their own controller.The pcie3.0 speeds are almost exactly half of the pcie4.0 speeds with m2 nvme ssds..Also you my set the pcie lanes speeds/bandwidth in bios, when your bios supports that....

author: kjr18
author_rank: Regular Contributor
timestamp: August 21, 2025, 07:34:34 am
content: What motherboard are you using? Your MB might have only pcie 3.0, or maybe pcie 4.0, but slot you put in your ssd might have less than 4 pcie lanes (speed of two pcie4.0 lanes is roughly the same as four lane pcie3.0). Also it might also depend on your cpu.

author: hans
author_rank: Super Contributor
timestamp: August 21, 2025, 08:51:52 am
content: Yep, also here to say probably PCIe3 and the drive is working as expected. Around 3750-3850MB/s is the speed which most PCIe drives run at with a maxed out PCIe3 bus.And to throw in some unsolicited advice: worrying about the >4000MB/s bit is a bit pointless. OS, software mostly still relies on 4K random read, in particular lightly queued workloads (so not the synthetic 32Threads IOPS variants). The 4K1T Random read has not dramatically improved in the last 10 years or so (perhaps with a factor of 2-3x). Even in loading times of games, which are reading large textures etc. from disk, iirc there is often not a huge gain from PCIe3 going forward, sometimes not even from a SATA-600 drive.A quicker drive would be faster for copying files or perhaps installing OS updates, but those are such background tasks for me I don't care about them.

author: SiliconWizard
author_rank: Super Contributor
timestamp: August 21, 2025, 12:45:27 pm
content: Quote from: Berni on August 21, 2025, 06:52:30 amExactly. Given the OP gets almost exactly half the bandwidth, I suspect this is 100% the problem.And even receent motherboards supporting PCIe 4.0 or even 5.0 don't have all their PCIe slots that support it, often some combinations are also exclusive, RTFM. And if not a "hardware" issue of that kind, could just be also a setting in the BIOS.

author: gamalot
author_rank: Super Contributor
timestamp: August 21, 2025, 01:24:54 pm
content: You are confusing memory and storage.

author: tom66
author_rank: Super Contributor
timestamp: August 21, 2025, 01:32:06 pm
content: Quote from: hans on August 21, 2025, 08:51:52 amTo this end, one of the best performance enhancements you can make to a PC is have way more RAM than you normally use. In both my work laptop and home PC I have 64GB. I rarely use more than 20-30GB with normal workloads, but having the extra RAM means that the OS can use it as a disk cache. Both Windows and Linux will greedily fill up the RAM with cached data; I can "read" some cached files at up to 20GB/s, and random IOPs will also be quite quick on the cache. This is also an area where faster RAM helps too.

author: raptor1956
author_rank: Frequent Contributor
timestamp: August 21, 2025, 06:22:12 pm
content: Quote from: Berni on August 21, 2025, 06:52:30 amThe documentation for the motherboard is pretty scant but I see no indication that any of the three NVME slots was different.The PC is a Minis Forum MS-A2 with 16C CPU and 96GB RAM and 2TB SSD in addition to the 4TB Samsung SSD.Brian

author: raptor1956
author_rank: Frequent Contributor
timestamp: August 21, 2025, 07:01:30 pm
content: Quote from: tom66 on August 21, 2025, 01:32:06 pm

author: raptor1956
author_rank: Frequent Contributor
timestamp: August 21, 2025, 07:04:55 pm
content: Quote from: gamalot on August 21, 2025, 01:24:54 pmYes, I read the Samsung Magician to indicate the SSD details when that portion covered the PC motherboard. The fact that Magician reported my system RAM as being made from 2 slots of 32GB when it is in fact 2 slots of 48GB for a total of 96GB, and then later in the same Magician program it listed the system RAM at 96GB -- something is not working properly with Magician.Brian

author: bte
author_rank: Regular Contributor
timestamp: August 21, 2025, 08:19:50 pm
content: Quote from: raptor1956 on August 21, 2025, 06:22:12 pmhttps://www.minisforum.com/products/minisforum-ms-a2says that the specs for the NVMe slots are not the same. Only one is guaranteed PCIe 4.0x4 speed, the others are PCIe 3.0x4 speed. See attached picture (the website had the specs as an image, not as text so I attached a cropped version of that spec image).

author: Berni
author_rank: Super Contributor
timestamp: August 22, 2025, 06:20:46 am
content: Quote from: raptor1956 on August 21, 2025, 06:22:12 pmYeah the manuals are not great, but the product page does mention it:https://www.minisforum.com/products/minisforum-ms-a2Seams like they are the correct PCie 4.0 x4 however by default two of the slots run in PCIe 3.0 mode and must be switched to 4.0 mode in the BIOS.

author: asmi
author_rank: Super Contributor
timestamp: August 23, 2025, 05:49:58 am
content: You can use free CrystalDiskInfo utility to figure out what interface is being used.