JUMP TO SOLUTION Solved

Original topic:

One 980 Pro is fast, another one is not

(Topic created: 10-19-2020 03:38 AM)
user60Yr0K51kH
Asteroid
Options
Monitors and Memory

I have two 980 Pro SSDs on my new build, an AMD 3900XT on an X570 motherboard. The C: drive is 500GB and the 😧 drive is 1TB. Magician benchmarks show write speed of 1141 the C: drive and 5244 for the 😧 drive. 

 

Is the C: drive defective, or did I misconfigure something?

Screenshot 2020-10-18 131952.png

0 Likes
Reply
8 Replies
ddaniel51
Comet
Options
Monitors and Memory

You have to account for the difference in cache size for the 500gb and 1tb drives.

Google some 980 pro cache tests to learn more.

 

0 Likes
Reply
user60Yr0K51kH
Asteroid
Options
Monitors and Memory

Naw, a 20% diff in cache size isn't going to account for a 500% performance delta. In some benchmarks the 1TB drive is twice as fast for sustained writes, but it's never anywhere close to five times faster.

 

Screenshot 2020-10-18 183933.png

0 Likes
Reply
ddaniel51
Comet
Options
Monitors and Memory

Oops, my bad.  Swap them between sockets then to insure performance follows the drive.

 

0 Likes
Reply
Options
Monitors and Memory

Hello user60Yr0K51kH,

Do you know if your motherboard is set to provide full PCIe bandwidth to both drives? Both of the m.2 slots need to provide at least 4 lanes of PCIe in order for the drives to give full performance. Check with the motherboard manufacturer that both M.2 slots have all the bandwidth they need and that the CPU can handle the bandwidth sharing between all the PCIe devices you may have installed.

0 Likes
Reply
user60Yr0K51kH
Asteroid
Options
Monitors and Memory

Yes, my MB enables one set of PCIe 4x4 lanes from the CPU and another set from the X570 chipset. The similarity in sequential read speeds from the two SSDs confirms that the MBs bandwidth is adequate.  

0 Likes
Reply
Options
Monitors and Memory

Hello user60Yr0K51kH,

 

I see, you are right, the performance of the drives is pretty similar when it comes to the random read and write too. Maybe there is something software realted, that may be bottlenecking the write performance of the drive. Have you tried turning off any write cache features your system may have active? Also have you tried checking any of the write caching policies for that drive within windows? 

0 Likes
Reply
user60Yr0K51kH
Asteroid
Options
Monitors and Memory

Write caching is enabled in Windows for both drives. The one weird thing I see is that Windows thinks the 500GB SSD is removeable but not the 1TB SSD. Of course, both drives are non-removeable but Windows is wack.

0 Likes
Reply
Solution
user60Yr0K51kH
Asteroid
Options
Monitors and Memory

The replacement drive I got from Amazon confirms that the original 500 GB 980 Pro is defective. It shows nearly the same read and write speeds as the 1 TB drive.

 

Sammy.png

View solution in context

0 Likes
Reply