DDR4 Memory Scaling & DDR4-3600 Testing With AMD Threadripper On Linux

[phoronix]

Phoronix: DDR4 Memory Scaling & DDR4-3600 Testing With AMD Threadripper On Linux

For those that may be looking at purchasing an AMD Threadripper this holiday season, especially with the recent price drops, here are some fresh memory tests on the Threadripper 1950X while running Debian GNU/Linux.

http://www.phoronix.com/vr.php?view=25566

[thelongdivider]

The scaling is actually very good for higher spec memory. More than I thought it might be.

[davidbepo]

The scaling is actually very good for higher spec memory. More than I thought it might be.

ryzen processors are memory starved due to infinity fabric. no surprises here

[Ehvis]

"The memory timings were not tweaked between the different frequency levels."

Can you clarify what that means? Because if it means that the timings were kept the same for tests, then the test would be a bit silly.

[carewolf]

Many of those "CPU" benchmark were better memory speed benchmarks than the official memory speed benchmark!

[coder111]

Hmm, it's a bit of a shame highest speed ECC memory I can find is DDR4-2666.

I'd love to have ECC, but if does look like it would be a substantial hit on performance... And probably my wallet as well.

[Kemosabe]

Does this mean any 4x configuration > 2x?

[droste]

"The memory timings were not tweaked between the different frequency levels."

Can you clarify what that means? Because if it means that the timings were kept the same for tests, then the test would be a bit silly.

Pretty sure he means they were not changed from the default value each stick has. As in "I didn't change anything in the bios".

[droste]

Does this mean any 4x configuration > 2x?

If you run them in quad-channel mode, yes. (and you don't try to run a 4x64MB configuration instead of 2x8GB configuration of course)

[Mark Rose]

The 4GB sticks are almost certainly single rank modules. Do you know if the 8 GB modules are single or dual rank? You can check by running `dmidecode | grep -oP "Rank: [1-4]+"`. Dual rank allows for more rank interleaving which can impact memory bandwidth.