Is Memtest86 memory speed estimation correct?

[AllexanderT]

Hi,

I test two very different PCs (see the screenshots):

• a mini PC with Intel Core i3-n305 CPU and 32 GB LPDDR5 4800 MT/s
• a desktop PC with Intel Core i7-13700F CPU and 64 GB DDR5 5200 MT/s.

As it is seen on the screenshots, the speed of the LPDDR memory is estimated as being higher compared to that of the desktop PC: 18.0 GB/s vs. 16.1 GB/s.
And yet, one full pass of the mini PC's 32 GB memory takes about 1:26 - 1:27 hours, while the 64 GB on the desktop PC are tested in little over 1:10 hours.
Is this misjudgment of the memory speed or am I missing something?

Best regards,
Alexander

[David (PassMark)]

Yes, this is slightly strange.

Both results (16 & 18GB/sec) are on the low side. Some new CPUs/RAM are hitting 40 to 50GB/sec. The memory controller on the i7-13700F wasn't the fastest, but I would have expected at least 25GB/sec. Maybe the 16GB/s makes sense for the low end n305.

CPU clock speed is also be reported as 2124Mhz on the 13700F. But it should be hitting 5200Mhz.
So couple of possibilities. BIOS settings are limiting clock speed. Or maybe these numbers are from the "efficiency cores" and not the "power" cores.

Overall testing speed can still be better on the 13700F however as it has more threads (but on the other hand it also has double the RAM to test).

Can you disable the efficiency cores in BIOS and try it?