RAM – slower clock speed when upgrading from 64GB to 128GB

[Martino_9]

Hello everyone,

I have a question about my EliteDesk 800 G8 Tower, MB HP 889 C / Q 570, i7-11700.

The PC is currently running with 64 GB DDR 4 Ram (2 x 32 GB Dual Channel @ 3200 MT/s). The HP technical data sheet states that with a maximum RAM allocation of 128 GB, the maximum clock rate is reduced to a maximum of 2933 MT/s

I'm guessing this is to ensure a stable system when MB/chipset hit their speed limit? Does anyone know exactly why this is the case when the system is actually designed for 3200 MHz and allows a maximum RAM allocation of 128 GB? But this question only in passing… 🙂  by the way,  The HP standard UEFI does not provide or allow any adjustments (e.g. manual setting, overclocking), not sure I would use such an option anyway, for stability reasons.

It would be more important to know: Does anyone have any experience with whether, and if so, the reduced clock rate is noticeably disadvantageous during operation? Only the measurable benchmarks are not important to me. A DAW runs on the PC and 64 GB RAM is sufficient for this without any problems, but I still want to do video editing with it and then the system would certainly reach its limits. Hence the extra RAM.

I don't want to buy RAM, then realize that the performance has dropped significantly and send the whole thing back even though the goods are ok. is. I don't like doing it.

Thanx in advance you for every helpful information and tips!

Kind regards

Martino

[NonSequitur777]

@Martino_9,

Welcome to our HP User Forum!

According to: https://ark.intel.com/content/www/us/en/ark/products/212279/intel-core-i711700-processor-16m-cache-u..., under "Memory Types", Intel says, and I quote:

"Intel® processors come in four different types: Single Channel, Dual Channel, Triple Channel, and Flex Mode. Maximum supported memory speed may be lower when populating multiple DIMMs per channel on products that support multiple memory channels." (emphasis added.)

1.) CPU Integrated Memory Controller (IMC) limitations: While the i7-11700 processor supports RAM speeds of up to 3200 MHz, there could be limitations in the CPU's IMC, or the specific configuration of your CPU and motherboard might not be optimal for reaching the maximum speed.

2.) XMP/DOCP not enabled: RAM modules often come with an XMP (Intel) or DOCP (AMD) profile that allows them to run at their rated speed. If the XMP/DOCP profile is not enabled in the BIOS, the RAM will run at the default ("SPD") speed, which can be anywhere between 2133 MHz and 2933 MHz.

3.) RAM compatibility issues: Sometimes, certain RAM modules might not be fully compatible with the motherboard or the CPU, leading to lower speeds being used to ensure stability.

Which brings me to the following HP EliteDesk 800 G8 Tower PC User performance links, which shows that this platform can indeed run specific RAM at 3200 MHz with 64GB all the way up to 128GB:

1.) https://www.userbenchmark.com/UserRun/47212419: 128GB at 3200 MHz using 2 x 32GB Samsung M378A4G43AB2-CWE and 2 x 32GB Micron 16ATF4G64AZ-3G2E1 RAM modules.

2.) https://www.userbenchmark.com/UserRun/49194670: 64GB at 3200 MHz, using 2 x 32GB Samsung M378A4G43AB2-CWE RAM modules.

3.) https://www.userbenchmark.com/UserRun/56007089: 64GB at 3200 MHz, using 2 x 32GB Hynix HMAA4GU6AJR8N-XN RAM modules.

Hope this was helpful.

Kind Regards,

NonSequitur777