Power Consumption and Thermals
Let's take a look at a couple of ATTO runs. First the SSD 750:
Now for the SM951 NVMe:
The SM951 sees a distinct advantage at smaller transfer sizes. Small file writes are far superior to the SSD 750, and read performance 'ramps up' far sooner than the Intel unit. Take note of how close those results are at the top end, especially the ultimate throughputs seen (the bottom few entries, which are large enough sizes to be more sequential than random). With those up for reference, I now direct you to the power consumption of both solutions as they turned in those above figures:
Wow! With very similar ultimate read and write performance, the SM951 is consuming roughly half the power of the SSD 750. It's almost a neat halving on just about everything from idle to random to larger transfers that behave more sequential in nature (the results at the right edge of the plot).
An additional note on idle consumption. The SM951 is rated at a much lower idle power figure (only 2mw), but that is only for the lower power state used on mobile platforms. This also negatively impacts response time as it takes the drive a bit more time to recover from this much lower power state. We chose to test as this SSD as it would be used in a default desktop configuration.
While it is far more power efficient, it doesn't have any heatsink area at all, and during sustained writes or heavy random IO, it will rise in temperature given the chance:
If you do manage to find one of these and put it into your desktop system, I'd recommend having at least *some* airflow passing across the M.2 slot. We saw no thermal throttling but with a fan at the slowest speed pointed towards the SM951, we recorded that 156F figure above. So long as we had minimal airflow across the M.2 slot, none the M.2 SSDs tested hit their thermal throttle limits, regardless of applied workload.
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.