Not a mission-critical troubleshooting issue by any means, but I am curious to know whether I am currently getting the most out of my Kingston HyperX M.2 drive.
The 240GB version is supposed to get 1,290 MB/s Reads and 600 MB/s Writes, and my current benches typically look like this: http://i.imgur.com/cteqelt.png (744 MB/sec READS, and 561 MB/sec WRITES)
I appreciate that my ASUS Z97-E motherboard only provides x2 PCIE lanes for its M.2 socket, but that should still allow a theoretical maximum of 1,000MB/sec, no?
I've updated the firmware, which caused no change in transfer speeds. I have no other SATA express devices attached, just a couple of SATA 3TB WD Reds.
Something is off with your BIOS settings. The M.2 slot is running in SATA mode, limiting you to 6GB/s (roughly 750MB/s)
Unfortunately I'm not really sure what setting and what to change it to. I had to deal with it myself when I built my current PC, but I simply forgot what exactly it was again. Sorry for that. I can reboot in 20 minutes to check mine.
I'm on an Z97 AsRock board and I've had both an AHCI based and NVMe based M.2 drive, and I've never seen that option for either drive. That seems really sloppy on MSI's part to have that option in the bios when a drive is installed. If your not on the latest bios I'd hope that it would have been removed and made automated which mode its in when a drive is installed.
Guess either way I stand corrected, I guess check that out OP. Still doesn't make sense that the drive would be reading at 500Mbps (within sata spec) and 700mbps (40% higher than sata spec), but would be in sata mode.
I did update my BIOS just a couple of months ago. After doing so I didn't have to touch the M.2 settings, so it does automatically select PCIE now whereas it would default to SATA in the earlier BIOS.
As for your edit : I seem to recall that SATA spec is 6Gbit/s, which translates to 750MB/s
Funny bit of info here : A year or so ago, NCIX tested some m.2 SSDs and found that they topped around 750MB/s, leading them to conclude that Samsung's claimed 2200MB/s read speed was wildly optimistic. No prizes for guessing what caused that
Still weird that there's the typical Sata over-head when he's reading, causing the 500MBps read, but that it doesn't apply to the write. What an assbackwards situation. But yeah I guess from what your saying this does look like the probable cause at this point.
I didn't remember this video, but upon opening it I had already disliked it lol.
Hopefully changing from SATA to PCIE won't mess up the drive... although I was thinking of reinstalling Windows 10 in UEFI mode just for the heck of it.
I changed the settings from AUTO to M.2, to make sure SATAEXPRESS wasn't the issue, but didn't see anything about changing the M.2 from SATA to PCIE. I did notice an NVME settings section, but it was greyed out.
My Reads improved by 8 - 10 MB/sec... but that's about it. I'm off to do some research on how well the Z97-E really implements PCIE in its M.2 slot. I suspect I may be stuck in SATA mode.
Personally I think the speeds you are getting might be best case at the moment. I think if you were to install the OS on a different drive and retest, you may get closer to your theoretical max.
You could be right, but, theoretically, PCIe 2.0 (even at x2) should get me 10 gigabits per second, so 1,250 MB/sec. Right now I'm getting ~750 MB/sec on a drive that claims to do 1,290 MB/sec.
Depends on the drive, Kingston may have taken the best possible numbers for advertising. Doesn't mean it will reach that. To me, that drive number is ALWAYS up to [insert claimed speeds here].
If this helps, I just benched a SATA Samsung 845DC EVO drive in the same system, and got 521.55 MB/sec Read, 390.92 MB/sec Write. (Samsung claims 530MB/sec and 460 MB/sec)
This is where it gets kind of weird and my knowledge on the subject matter is somewhat limited. Here is a good article explaining why. My instant thought would be why the Titan XP has a larger buss than the GTX 1080 Ti when there is 1 GB less VRAM.
The weird thing is, on the Kingston HyperX drives, it's only the Writes that increase between the 240GB and 480GB drives.
Compressible Data Transfer (ATTO)
240GB — 1400MB/s Read and 600MB/s Write
480GB — 1400MB/s Read and 1000MB/s Write
960GB — 1350MB/s Read and 1000MB/s Write
Actually now that you've flipped the numbers, I think this is actually correct and I agree with Novasty. I Had an Sm951 which is a x4 pcie gen 3.0 in my x2 slot on my motherboard before I gave it to my brother, and your numbers are about on par with what I used it get. Your numbers also match what the Early plextor M6Pe got, which was really the first M.2 SSD I ever heard about. That drive was a gen 2 x2, and your currently limited to gen 2 x2 because of the motherboard.
I will also note that in AS-SSD the 240GB Model of the Hyper X Predator is listed as having a roughly 1290MBps read and 600Mbps write on the newegg page found here. The other models on the site do seem to have updated numbers based on capacity, so I believe that the numbers on the newegg page would be indicitive of the 240gb capacity and not just the largest capacity. You can find that page here:
I will briefly address why smaller SSD's are slower, since that cameup (although I do not believe it is why this drive in particular is slower). Basically, in the simplest way of explaining it, its like Raid 0 but natively between chips of NAND Flash on the SSD. Your splitting the writing and reading between more Flash cells to achieve a total higher read and write, since the palatalization allows for the combination of the individual read and write speeds of all the cells. In the world of M.2 you can run into controller vs nand speed limitations, since we're not at the point like we are with Sata 3 where on the top end we saturate the physical bus before we fully max out what the drive can do. But, in this case, I do think it is a bus limitation.
Theoretically the bus should yes operate at 1000MBps, but that is not including the overhead used for controlling the drive. The Predator is running AHCI over PCIE I believe, which takes a bit more off the top then a newer protocol like NVMe would. Not all M.2 run NVMe. My SM951 was AHCI, and over the same bus limitation it basically matched your numbers. I don't think I have a picture on hand, but I can look.
