Tweet
We see a lot of RAM related performance problems. So we thought it was worth quantifying how much of an impact the RAM configuration can have on the benchmark results.
The two main issues are:
Accidentally running in single channel
Most motherboards offer dual, tri or quad channel support. RAM access can be interleaved in dual channel mode. So they work faster with 2 or more sticks, but only when the sticks are in the correct slots. It is a common problem with cheap machines that they ship with just 1 RAM stick, preventing dual channel mode from working. So check the motherboard manual for the optimal slot usage.
BIOS setup
Another common problem is the BIOS configuration for the RAM. Vendors often select a safe (slow) default settings for timings and clock speeds. There is often a setting in BIOS to select a faster "XMP profile". A XMP profile is a collection of faster settings that should be safe to use, as they were validated by the RAM vendor. For advanced users who don't mind of bit of instability you can manually set the clock speeds, timings, voltages & gear selection. Generally using one of the XMP profiles is sufficient however.
Finally make sure you have enough RAM to avoid running out and forcing the operating system to swap memory pages out to disk. 8GB is really a bare minimum for Windows 11. Not having enough RAM can be devastatingly bad for performance, but once you have 'enough' adding more doesn't improve performance. (More RAM does not equal fast RAM).
RAM benchmark results with PerformanceTest using different RAM setups on the same machine (DDR4 RAM).
This is just an indicative example. Different CPUs and different RAM will give different results.
Another interesting element in the results is that 1 CPU core doesn't max out the RAM's bandwidth.
The two main issues are:
Accidentally running in single channel
Most motherboards offer dual, tri or quad channel support. RAM access can be interleaved in dual channel mode. So they work faster with 2 or more sticks, but only when the sticks are in the correct slots. It is a common problem with cheap machines that they ship with just 1 RAM stick, preventing dual channel mode from working. So check the motherboard manual for the optimal slot usage.
BIOS setup
Another common problem is the BIOS configuration for the RAM. Vendors often select a safe (slow) default settings for timings and clock speeds. There is often a setting in BIOS to select a faster "XMP profile". A XMP profile is a collection of faster settings that should be safe to use, as they were validated by the RAM vendor. For advanced users who don't mind of bit of instability you can manually set the clock speeds, timings, voltages & gear selection. Generally using one of the XMP profiles is sufficient however.
Finally make sure you have enough RAM to avoid running out and forcing the operating system to swap memory pages out to disk. 8GB is really a bare minimum for Windows 11. Not having enough RAM can be devastatingly bad for performance, but once you have 'enough' adding more doesn't improve performance. (More RAM does not equal fast RAM).
RAM benchmark results with PerformanceTest using different RAM setups on the same machine (DDR4 RAM).
| RAM Test | 1 Stick Default Settings Single channel |
2 Sticks Default Settings Dual Channel |
2 Sticks XMP Profile 1 Dual channel |
2 Sticks XMP Profile 2 Dual channel |
Percentage improvement Worst vs Best result |
| Read (MB/sec, 1 CPU core) | 17161 | 17416 | 17808 | 18551 | 8.1% |
| Write (MB/sec, 1 CPU core) | 7983 | 8351 | 8397 | 8512 | 6.6% |
| Latency (nano sec) | 43 | 43 | 43 | 43 | 0% |
| Multi-Threaded (MB/sec) | 19923 | 27499 | 27854 | 28809 | 44% |
This is just an indicative example. Different CPUs and different RAM will give different results.
Another interesting element in the results is that 1 CPU core doesn't max out the RAM's bandwidth.