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Your next PC should have a PCI Express SSD

Matthew Mombrea | Aug. 20, 2015
When performance exceeds bandwidth.

Credit: Intel

Historically the desktop storage communication channel (ATA, SATA, SATA II, SATA III) has outpaced the speed of the storage devices themselves:

  • PATA - ~150 MB/sec
  • SATA - 150 MB /sec
  • SATA II - 300 MB/sec
  • SATA III - 600 MB/sec 

That's still mostly true today for mechanical hard drives as well as SATA III based SSD's but a new class of SSD is becoming affordable to the average consumer - PCIe SSD. 

Using the PCI Express channel which has become standard on motherboards over the past decade, the PCIe SSD gains additional bandwidth using the faster interface combined with advances in flash storage and an emerging standard called Non-Volatile Memory Express (NVMe). 


These video card looking hard drives are capable of far greater throughput than their SATA counterparts when inserted into a PCI Express v3.0 slot on your motherboard. What used to be out of the budget of a home PC is slowly creeping into feasibility now. The above Intel SSD 750 PCIe 400GB card can be yours for around $389 today. True, that's still almost double the price of a standard 400GB SATA III SSD but it's not exactly pocket shattering. Still, why would you want such a thing if it's double the price? Here's the answer in one chart:

intel ssd data center family 
Click the image to enlarge. Credit: Intel

You're reading that right, up to 2,900 MB/sec read throughput and 460,000 IOPS and extremely low latency.

If you have a high I/O workload these drives are for you at a relatively small premium over SATA SSDs.

The fact that these cards are the size of a video card and take up a PCIe slot is cause for concern for gaming rigs or workstations running 2 or 3 graphics cards however. Aside from the slot and space it takes up, it's also consuming a portion of the overall PCIe pipe that's normally dedicated to the GPUs. You're going to want the latest Intel chipset on your motherboard that you can get to take advantage of this card and reduce bottlenecks. Today that's the X99 chipset (Haswell-E) which has 40 PCIe v3.0 lanes. You can get away with the more common Z97 Haswell chipset but you won't be able to maximize the potential of the drives. This will become less of an issue with the upcoming Skylake processors and the x100 chipset which have more lanes and ample bandwidth for PCIe SSDs.

There's still the question of space however, and there is another form factor available for these drives in a more traditional 2.5" disk, the example below from OCZ.


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