Weird Results from HDTUNE with NEW NVME M.2 SSD

School Appropriate · June 3, 2020

So guys, I recently cloned an old intel SATA SSD to a WD Blue SN550 NVME drive. I then placed the drive into a PCIE 3.0 adapter, from M.2 to PCIE 3.0x4, and then I plugged that into my Asus Maximus 6 Formula motherboard. After that was done I ran TRIM on the NVME drive and then ran HDTUNE bench mark and got this...

So what happened?

NewMaxx · June 3, 2020

Hmm, that is strange. The drive is only rated for 950 MB/s (SLC sequential write) at that capacity due to its denser flash although technically it can spike up to 1250 MB/s, the TLC speeds should be in the 250-300 MB/s range. The SLC is static and probably ~6GB in size. Normally in HD Tune (possibly need Pro) I run "Full test" at maximum "Accurate" with a 128 KB block size to test the SLC response.

School Appropriate · June 4, 2020

15 hours ago, NewMaxx said:

Hmm, that is strange. The drive is only rated for 950 MB/s (SLC sequential write) at that capacity due to its denser flash although technically it can spike up to 1250 MB/s, the TLC speeds should be in the 250-300 MB/s range. The SLC is static and probably ~6GB in size. Normally in HD Tune (possibly need Pro) I run "Full test" at maximum "Accurate" with a 128 KB block size to test the SLC response.

I upgraded to a Gigabyte Aorus Elite 570 which supports NVME drives natively, and ran the test again, same result. I ran the test your way though, and instead of the lows being at 300MBPS, the lows were 500.

NewMaxx · June 4, 2020

Here is my result for the 1TB SKU. That version actually has a 12.5GB SLC which I graphed here if you want to test it on yours (it should be 1/4th that on the 250GB SKU). You can see from AnandTech's results for the 250GB SN500 - which should be faster since the flash is less dense - that it still doesn't hit your speeds. Seems like some sort of caching is going on or something else.