Hi guys
Sometimes my RAID 0 SATA SSD array is extremely slow. Then, maybe 15min later or after rebooting, it works fine again.
This is how it looks when it's slow:
This is the normal speed:
My relevant specs are:
Ryzen 7 1800x
Asus Crosshair VI Hero (RAID on X370 chipset)
2x Radeon R7 240GB SSDs (in RAID 0)
Windows 10 Pro N 1709
AMD AHCI RAID driver 9.2.0.0070
RAID 0 with Read + Write Back Cache
It's a really bad idea to RAID0 your boot drive, even though SSDs are far more reliable than HDDs it's still a bad idea. Also, you shouldn't always take benchmark results at face value, especially if you only run them once. If they're to be believed your sequential performance is better than mine, despite me having Samsung 850 EVOs which are -much- faster than the R7 SSDs you use.
Comparison: 512GB 960 Pro:
I'm completely aware of the (usual) consequences of running RAID 0. I have no data on it that I mind losing, which isn't backed up constantly.
It depends if you're running the SATA version of 850 EVO and if you're running hardware RAID or a software emulation of RAID (like Windows Storage Spaces). It can have various other reasons why results from one system to another might differ.
Generally, sequential speeds of SATA SSDs is often limited by the SATA bandwidth.
According to this review, my SSDs should perform similarly to SATA 850 EVOs:
AMD Radeon R7 SSD (240GB) Review
I get similar results for 5 runs, it seems to be accurate. Also keep in mind that you're running a different version of CrystalDiskMark with the Seq Q1T1 test replaced by a 4KiB Q8T8 test and in a different order.
Yes I'm using the newer version, as you should be. Also no, it's not, they're 30% faster.
Which is why Anandtech came to this conclusion:
These drives were -never- a good idea, costing more than a Samsung Evo drive, yet performing worse. That's why AMD quickly discontinued them, and why https://www.amd.com/en-us/products/solid-state-drives does not exist anymore.
The Radeon SSD is basically an ARC 100, which is a completely fine drive. It uses MLC instead of TLC of the Samsung EVO and thus has faster sustained reads and writes. The controller is a bit better on the EVO and it has some nice software features like rapid mode, but the 850 EVOs were substantially more expensive at the time then the Radeon drives.
I'm not sure why you're comparing a 1TB SSD with a 240GB SSD, the larger drives are usually faster. These are the Userbench scores of the 250GB version, where you can also see the ~50% higher throughput of the Radeon SSD:
Without RAID, it's impossible to reach 1TB/s on SATA III, as the theoretical limit of SATA III is 6Gb/s.
