I've been using a SATA one myself for a few years now, and sometimes I wonder how PCIe could be even faster.
Oh, it
is. The new computers we built for Kati and Cranky both use PCIe SSDs instead of SATA.
Here, let me throw some numbers at you:
As a reference, a standard HDD's fastest read/write is about 150MB/s and 200-ish IO/s (input/output or transactions per second)
SATA SSDs are all limited by the SATA-III bus speed (and the AHCI protocol), and so will max out at ~525-550MB/s and 90k IO/s. As you can see, the biggest benefit of getting an SSD is not as much the transfer speed increase (3-4x) as it is the SSD's ability to go from here to there and then to there with almost no delay whatsoever compared to the HDD (450x increase!).
Kati's
(Gen1 AHCI) 240GB HyperX Predator has a read/write speed of 1300/600 MB/s* and averages about 100k IO/s. The increase in IO/s is not very large (if you can call a 10k/s increase "not very large"), but because the drive communicates directly over the PCIe bus rather than SATA, it has up to 2000MB/s bandwidth to play with (PCIe v2.0 has 500MB bandwidth per lane, and the drive is wired for 4 lanes), which leaves SATA's 600MB theoretical maximum faaaaar behind.
Cranky's computer takes this even further with his
NVMe Intel 750 400GB card. First of all, it is fully PCIe v3.0 capable, which means it has 4000MB/s bandwidth to play with (PCIe v3.0 has 1GB/s bandwidth per lane, 2x that of v2.0, and the drive is wired for 4 lanes). It has a read/write speed of 2200/900 MB/s** which is about 50% faster than Kati's drive BUT again it's the IO/s where the real speedup occurs. The Intel 750 averages WELL OVER 300K IO/s (thanks to the newer NVMe protocol), which is absolutely
ludicrous for a desktop computer.
tl;dr: My computer, which has a pair of
1TB WD RE3's (basically the enterprise version of WD Black) in a RAID-1 for redundancy and faster reads, boots from a cold start up to the desktop in about 30-35 seconds (though admittedly that includes waiting through all the BIOS screens).
Kati's computer is at the desktop in less than 10 seconds. Cranky's is up in under 6.
The place you can really see this difference is in Minecraft, because Minecraft has to load chunks from disk in order to display them on your screen. On Cranky's computer, distant terrain is just...there. Even at a view distance of 32 chunks, they just fill right in in under a second.
--Patrick
*It is hamstrung by being only the 240GB version, the 480GB version can do 1300/1000 MB/s BUT at the time it was much more expensive.
**Again, hamstrung by being the smallest capacity, the 1.2TB version can do 2400/1200 MB/s BUT was almost twice the price.
