Intel SSD 750 PCIe SSD Review: NVMe for the Client
by Kristian Vättö on April 2, 2015 12:00 PM ESTSequential Read Performance
Our sequential tests are conducted in the same manner as our random IO tests. Each queue depth is tested for three minutes without any idle time in between the tests and the IOs are 4K aligned similar to what you would experience in a typical desktop OS.
In sequential read performance the SM951 keeps its lead. While the SSD 750 reaches up to 2.75GB/s at high queue depths, the scaling at small queue depths is very poor. I think this is an area where Intel should have put in a little more effort because it would translate to better performance in more typical workloads.
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Sequential Write Performance
Sequential write testing differs from random testing in the sense that the LBA span is not limited. That's because sequential IOs don't fragment the drive, so the performance will be at its peak regardless.
The SSD 750 is faster in sequential writes than the SM951, but the difference isn't all that big when you take into account that the SSD 750 has more than twice the amount of NAND. The SM951 did have some throttling issues as you can see in the graph below and I bet that with a heatsink and proper cooling the two would be quite identical because at queue depth of 1 the SSD 750 is only marginally faster. It's again a bit disappointing that the SSD 750 isn't that well optimized for sequential IO because there's prcatically no scaling at all and the drive maxes out at ~1350MB/s.
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knweiss - Thursday, April 2, 2015 - link
Kristian, you wrote "for up to 4GB/s of bandwidth with PCIe 3.0 (although in real world the maximum bandwidth is about 3.2GB/s due to PCIe inefficiency)". Is this really true? PCIe 2.0 uses 8b/10b encoding with 20% bandwidth overhead which would match your numbers. However, PCIe 3.0 uses 128b/130b encoding with only 1.54% bandwidth overhead. Could you please explain the inefficiency you mentioned? Thanks in advance!DanNeely - Thursday, April 2, 2015 - link
The real world number includes the bandwidth consumed by PCIe packet headers, NVME packet headers, NVME command messages, etc. Those are over and above the penalty from the encoding scheme on the bus itself.IntelUser2000 - Thursday, April 2, 2015 - link
The 4GB bandwidth takes into account the encoding scheme.Each lane of v1 PCI-Express had 2.5GT/s so with 8b/10b encoding you end up with 2.5G/10 = 250MB/s. Quadruple that for four lanes and you end up with 1GB/s.
v2 of PCI-Express is double that and v3 of PCI-Express is further double that and there is the 4GB number.
aggrokalle - Thursday, April 2, 2015 - link
i'm interrested in this as well...so how many nand-channels got the 1.2tb and 400gb version Kristian?tspacie - Thursday, April 2, 2015 - link
Was there an approximate release date?gforce007 - Thursday, April 2, 2015 - link
When will these be available for purchase? Also I have a m.2 slot on my motherboard (z10PE-D8 WS) Id rather utilize the 2.5 15mm form factor. I am a bit confused. I dont think that board has SFF-8639. Is there an adapter. Will that affect performance? I assume so and by how much?knweiss - Thursday, April 2, 2015 - link
The motherboard (host) end of the cable has a square-shaped SFF-8643(!) connector. E.g. ASUS ships an M.2 adapter card for the X99 Sabertooth that offers a suitable port. SFF-8639 is on the drive's end.emn13 - Thursday, April 2, 2015 - link
That endurance number is scarily low for a 1.2TB drive. 70GB a day for 5 years - thats about 128 TB of writes total, and that's just 100 drive writes! Put another way, at around 1GB/sec (which this drive can easily do), you'd reach those 100 drive writes in just 36 hours.Of course, that's an extremely intensive workload, but I sure hope this is just intel trying to avoid giving any warrantee rather than an every remotely realistic assessment of the drives capabilities.
p1esk - Thursday, April 2, 2015 - link
This is a consumer drive. What's your use case where you write more than 70GB a day?juhatus - Friday, April 3, 2015 - link
Raw 4k video and its not even close to being enough.At 4K (4096 x 2160) it registers 1697 Mbps which equals 764 GB/hour of 4K video footage. A single camera large Hollywood production can often shoot 100 hours of footage. That’s 76 TB of 4K ProRes 4444 XQ footage.
The upcoming David Fincher film GONE GIRL crept up on 500 hours of raw footage during its multi camera 6K RED Dragon production. That equates to roughly 315 TB of RED 6K (4:1) footage. Shit just got real for data management and post production workflows.