Introduction, Specifications and Packaging
We got our hands on an NVMe SM951! How does it stack up?
Introduction:
There's been a lot of recent talk about the Samsung SM951 M.2 PCIe SSD. It was supposed to launch as an NVMe product, but ended up coming out in AHCI form. We can only assume that Samsung chose to hold back on their NVMe-capable iteration because many devices are unable to boot fron an NVMe SSD. Sitting back for a few months was a wise choice in this case, as an NVMe-only version would limit the OEM products that could equip it. That new variant did finally end up launching, and we have rounded it and the other Samsung M.2 PCIe SSDs up for some much awaited testing:
I'll be comparing the three above units against some other PCIe SSDs, including the Intel SSD 750, Kingston HyperX Predator, G.Skill Phoenix Blade, Plextor M6e Black, and more!
Continue reading our review of these hot new M.2 products!
Specifications:
These are all OEM products, but here are some specs from various sources:
XP941 (source):
- Form Factor: M.2 2280
- Capacity (GB): 128, 256, 512
- Host Interface: PCI-Express 2.0 x4
- MTBF: 1.5 Million Hours
- Uncorrectable Bit Error Rate (UBER): < 1 sector per 1015 bits read
- Power Consumption (Active/Idle): 5.8W / 80mW
- Peak Read Sequential Performance: Up to 1170 MB/s
- Peak Write Sequential Performance: Up to 930 MB/s
- Peak Random Performance Reads: Up to 122k IOPS
- Peak Random Performance Writes: Up to 72k IOPS
- Physical Dimesions: 22 x 80 x 4 mm
- Weight: 8.5g
SM951 (AHCI) (source):
- Form Factor: M.2 2280
- Capacity (GB): 128, 256, 512
- Host Interface: PCI-Express 3.0 x4
- Controller: Samsung UBX 3-Core
- Flash: Samsung 16nm MLC
- Power Consumption (Active/Idle): 6.5W / 50mW
- Peak Read Sequential Performance: 2050, 2150, 2150 MB/s
- Peak Write Sequential Performance 600, 1200, 1500 MB/s
- Peak Random Performance Reads: 90k IOPS
- Peak Random Performance Writes: 70k IOPS
- Physical Dimesions: 22 x 80 x 4 mm
SM951 (NVMe) (source):
- Form Factor: M.2 2280
- Capacity (GB): 256, 512
- Host Interface: PCI-Express 3.0 x4
- Flash: Samsung 16nm MLC (verified visually)
- Peak Read Sequential Performance: 1.08, 1.17 GB/s *
- Peak Write Sequential Performance 800, 931 MB/s *
- Peak Random Performance Reads: 120k, 122k IOPS
- Peak Random Performance Writes: 60k, 72k IOPS
- Physical Dimesions: 22 x 80 x 4 mm
* We know the NVMe SM951 has higher specs than what was stated in our source, but we don't have more accurate figures from Samsung.
Packaging:
Our NVMe SM951 was 'packaged' with another product we got in for testing.
The AHCI SM951 came in a 2015 Lenovo X1 Carbon that Ryan has been testing. I liberated it while he wasn't looking (shhh).
The XP941 came with another product, but we have a brown box pic for that one:
Hey Allyn,
I approach most of
Hey Allyn,
I approach most of this from a gamer’s perspective. Of course, I wouldn’t expect night and day difference with a very high end SSD vs a normal SSD. But what about for something like running around Skyrim with a butt-ton of mods? Open world games, tons of things to load on the fly.
It could still be CPU bottlenecked though. Tom’s Hardware did an article a long time ago about SSD load in gaming. The guy used some sort of trace-based analysis tool from Intel to check if the reads from the SSD during game startup, level loading, and playtime are sequential or random, what size, and what queue depth. It’s very interesting and I think many gamers would like to see such an article.
I’m looking at all the graphs and frankly it doesn’t mean much to me. I don’t run file servers, I load a ton of maps.
Thanks
Great review. I was hoping
Great review. I was hoping you could help out by comparing my workflow to which above benchmark best applies to me.
My apps use up to 29GBs of RAM where 1000s of 64k buffers are used as targets for various streams of audio stored on SSDs.
When I press a key on an 88 note keyboard/synth it goes 1st to the 64k buffer in RAM then a stream of audio follows.
Obviuosly random applies to the 64k RAM buffers and read to the streaming audio files.
Maybe the Workstation benchmark….?
Thanks again for a great source of comparisons on SSDs.
The X99 Sabertooth allow one
The X99 Sabertooth allow one to conceal their M.2 SSD completely under the Thermal Armor. Is that recommended given the heat output for SM951 NVMe?
HAPPY HAPPY JOY JOY!!!
HAPPY HAPPY JOY JOY!!!
Have you heard about a 1TB
Have you heard about a 1TB version of the SM951 being release soon?
I’m using the SM951 ACHI in a
I’m using the SM951 ACHI in a m.2 to PCI x4 card that has a heatsink on it and is plugged into a x4 PCI-E slot on my x99 motherboard. I love it but I’m wondering if I managed to get my hands on one of the new NVME, would it fit into the same heatsink slot (the pins looks the same) or would I have to use the M.2 slot on the motherboard? I’m assuming either would work and just change to NVME in the BIOS.
Second, I have two Samsung 850 pros running in RAID 0 as my applications drive. Would I still be able to keep this in RAID while using NVME on the Asus x99 motherboard?
Hello, I’ve just been
Hello, I’ve just been comparing a 512GB 951 NVMe variant that I purchased yesterday with an existing 512GB 951 AHCI. Apparently it’s a sample rather than a production unit but I’m seeing fantastic read speeds but horrific write speeds. In my case I’m using with an Asus Z97i-plus with the latest BIOS. The board identifies the 951 and allows me to install windows (8.1 all latest updates)… so far so good. Unfortunately when I run speed tests against the NVMe variant I get 10 times slower write speeds compared to the AHCI 951.
CrystalDiskMark: AHCI variant (connected to PCIe 3.0 bus)
Seq Q32T1 – 1172MB/s read | 1043MB/s write
4k Q32T1 – 398MB/s read | 289MB/s write
Seq – 1052MB/s read | 900MB/s write
4k – 35MB/s read | 128MB/s write
CrystalDiskMark: NVMe variant (connected to PCIe 3.0 bus)
Seq Q32T1 – 2264MB/s read | 501MB/s write
4k Q32T1 – 563 MB/s read | 21 MB/s write
Seq – 1299 MB/s read | 170 MB/s write
4k – 54 MB/s read | 0.98 MB/s write
Blindingly fast read but horrifically slow write speeds.
I’ve also tested using the Z97i-plus’s M.2 slot. I see reduced read speeds due to the limited, 10Gbps, speed of the M.2 on this board but the same horrific write speeds.
Is there something that I might be doing wrong? Could this be a BIOS problem? A Windows NVMe driver problem?
That’s odd, but I believe
That's odd, but I believe Kristian from Anandtech had a similar issue with one of his samples. It was an actual defect I believe and they had to swap out his sample, IIRC.