Curious about memory issues

[VulcanRidr]

I'm trying to figure out if I have an actual problem here or if I am chasing ghosts.

I just upgraded my system after 8 years. I was running an i7-6850k with 64GB (4 16GB sticks) of DDR4-2133 RAM. I just upgraded to a Ryzen 7 5800x with 64GB (2 32GB sticks) of DDR4-3200 RAM.

I installed a benchmarking program, ubench, just to get an apples-to-apples performance comparison of the system before and after. No other hardware was changed, only motherboard (asus X99a -> asus prime b550-plus), cpu, and ram. I turned on DCOP in the bios for the new board, and the memory is running at 3200MHz, turned on the Asus memory enhancement, and the timing numbers are 22-22-22-52-1.2v.

However, the thing i noticed was that while the cpu benchmarked about 2.5x faster, the DDR4-3200 memory was about 33% slower than the 2133 memory.

So ubench gave me the following numbers:

i7/ddr4-2133
Ubench CPU:  5072151
Ubench MEM:  9886859

ryzen 5800x
Ubench CPU: 12451785
Ubench MEM:  6377351

So I am wondering if this could be

• A problem with the benchmark program (e.g. ubench out of date or maybe different behavior on amd vs intel);
• More channels or whatever owing to 4 sticks of memory vs 2;
• Something still b0rked up with the memory config in bios;
• Bad memory

Does anyone who has more experience or familiarity with modern memory have any thoughts on this?

Thanks!

 

[cracauer@]

I am not familiar with that benchmark. It is possible that it is favoring Intel. Intel CPUs often do better in memory benchmarks than AMD, although that doesn't translate to actual work getting done by the CPU as a whole. Your Intel CPU does only have dual-channel RAM.

My go-to memory benchmark is SuperPi.

I would not use any of the Asus-specific memory settings. I either run stock (as in CPU stock) or I do proper overclocking with extensive validation.

 

[delta0]

A few questions:

1. Here's the memory compatibility matrix for your specific motherboard. Do you see your RAM modules listed as compatible?
2. What BIOS version is your motherboard running? I see version 1216 is the last update that declares improved RAM compatibility. Newer versions than that exist at this time with the latest being from late 2024.
3. Here is the user's guide for your motherboard. PDF page 20 notes optimal placement of the DIMMs in an alternating pattern. Are you in that pattern?

- D

 

[tingo]

there are lies, damn lies, statistics and then benchmark programs. What was the question again?

 

[VulcanRidr]

I am not familiar with that benchmark. It is possible that it is favoring Intel. Intel CPUs often do better in memory benchmarks than AMD, although that doesn't translate to actual work getting done by the CPU as a whole. Your Intel CPU does only have dual-channel RAM.

My go-to memory benchmark is SuperPi.

Technically, it is too late to do any benchmarking since I am not going to re-gut the system and go back to the old setup, just for comparison. I just wanted a sanity check as to whether I was chasing ghosts or if it was an actual problem.

I would not use any of the Asus-specific memory settings. I either run stock (as in CPU stock) or I do proper overclocking with extensive validation.

I just did it as a test, and it appears to make zero difference. It is still reading approximately the same, so I am guessing it did not bump up the settings above stock, the benchmarks are pretty much the same.

Here's the memory compatibility matrix for your specific motherboard. Do you see your RAM modules listed as compatible?

I actually ended up ordering the Corsair Vengeance DDR4-3600 that were listed on the compat matrix, which the Crucial Pro was not.

What BIOS version is your motherboard running? I see version 1216 is the last update that declares improved RAM compatibility. Newer versions than that exist at this time with the latest being from late 2024.

It is running 3607, from 20240322, according to dmidecode. Not the latest and greatest, one rev behind, but close enough for the time being.

Here is the user's guide for your motherboard. PDF page 20 notes optimal placement of the DIMMs in an alternating pattern. Are you in that pattern?

I am. A2 and B2...

I will report back when I get the replacement RAM.