Intel 750 Series 400GB Versus Samsung SM951 512GB

We're pitting Intel's 400GB SSD 750 against Samsung's 512GB SM951 because they're the fastest PCIe-based drives in their respective categories today.

By Chris Ramseyer
published

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Sequential Read

Intel 750 Series 1.2TB

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Samsung SM951 512GB SSD

To read about our storage tests in-depth, please check out How We Test HDDs And SSDs. Four-corner testing is covered on page six.

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We first noticed a dip in QD2 sequential read performance on the 1.2TB SSD 750 just prior to publishing our review. We ran an additional test to verify our initial results. Unfortunately, the 400GB model encounters the same hit, and performance drops off lower than sequential reads at QD1 and QD4. 

Samsung's SM951 512GB delivers higher sequential read performance at lower queue depths, but can't match the same peak numbers as Intel's SSD 750 at high queue depths.

It's important to understand that most client workloads happen at low queue depths. Drive vendors typically don't specify performance at those queue depths, where it really counts. And we don't blame them. Peaks always looks better on paper. They just don't always represent usable performance.

Chris Ramseyer
Chris Ramseyer
Chris Ramseyer is a Contributing Editor for Tom's Hardware US. He tests and reviews consumer storage.
24 Comments Comment from the forums
  • dark_wizzie
    Hey, I would love to see a new article about trace-based analysis of hard drive load. I've got some money to splurge on storage I don't strictly NEED, but actually I have no idea what to buy. Just a thought. :)
    Reply
  • Arabian Knight
    agaiiiin

    How about testing the Intel 750 card in Raid 0 ?

    please add another Card and try software raid .
    Reply
  • PaulBags
    RE: Sequential Steady State, what is the percent scale in that graph? I assume one end is writes and one read, but which? Graph needs to be properly labeled.
    Reply
  • PaulBags
    Sequential steady state vs random steady state, switching between IOPs and MB/s, yay that's comparible. Bah, I'm done with this article. Bppppppt.
    Reply
  • jedimindtriks
    flexxmemory.co.uk has the sm951 for 350$
    Reply
  • Blueberries
    I'd take a 750 over the SM951 any day, you just can't beat the latency and random read/write performance. The SM951 is probably hands down the best SSD right now for the typical PC user, all things considered; having neck-and-neck or better performance at low queue depths and of course a much faster boot time.

    Get the 750 if you're an enthusiast and you can afford it. Otherwise the SM951 is going to be the best performance you've experienced in your life.
    Reply
  • Osiricat
    Hi! Anything about temps? I read in earliers reviews that SM951 warms up to 70-75ºC, for some reason intel added passive cooling over theirs memory chips!
    Reply
  • CRamseyer
    The industry standard is to measure random performance in IOPS and sequential performance in throughput. Why would you want to compare sequential IOPS to random IOPS or sequential throughput to random throughput?

    The sequential steady state shows read percentage. 100% read to 0% read. It's mainly an enterprise test I imported a few years ago in my testing to see the bathtub curve of the devices under test.

    As for RAID with these drives. I'm not sure if a RAID Report is really needed. You can't boot from devices in Windows software RAID. If 5% of the market cares about these premium parts to start with then RAID performance has to amount to 5 to 10% of those readers. I don't think there are enough readers to justify the time and expense for that level of testing. If Intel wants to provide the parts I don't mind testing and writing the article.

    Chris
    Reply
  • PaulBags
    15929620 said:
    The industry standard is to measure random performance in IOPS and sequential performance in throughput. Why would you want to compare sequential IOPS to random IOPS or sequential throughput to random throughput?

    ...

    Chris
    So that I can see the difference? How much of a performance drop is there with random vs sequential? Yes I don't get to decide how my data travels, but is random throughput significantly above the sata 6gb ceiling or does interface not _really_ matter yet unless you have a lot of sequential reads/writes to do? Additionally, what kind of performance is there when there is mixed sequential and random; somewhere in between the two or would comparing the two be completely irrelevant?
    Reply
  • CRamseyer
    Random performance is never higher than the limits of SATA 6Gbps unless you have a product like the Memblaze or P320H that can deliver full PCIe bandwidth random 4K reads and writes. Those are both enterprise products that cost more than a used Honda.

    Measuring 4K data in throughput is like telling someone the length of a dollar bill in miles.
    Reply