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fajin yu
Asked: 2019-05-24 21:20:19 +0800 CST

How can I know my memory's "actual frequency" in ubuntu?

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I bought some memory stick which is ovcerclockable. The default frequency is 2.4GHz, the frequency can be configured up to 3.6GHz. And I confiured frequency and the voltage in BIOS, set the frequency to 3.6GHz. Then I ran the memtester86 8.1, to test if overclocking is stable, and it passed all test with no error on 3.6 GHz. Finally, I entery the OS(my OS version is 18.04),and execue sudo dmidecode --type 17 | grep -i speed, it shows like below:

Speed: 2400 MT/s
Configured Clock Speed: 3600 MT/s
Speed: 2400 MT/s
Configured Clock Speed: 3600 MT/s
Speed: 2400 MT/s
Configured Clock Speed: 3600 MT/s
Speed: 2400 MT/s
Configured Clock Speed: 3600 MT/s
Speed: 2400 MT/s
Configured Clock Speed: 3600 MT/s
Speed: 2400 MT/s
Configured Clock Speed: 3600 MT/s
Speed: 2400 MT/s
Configured Clock Speed: 3600 MT/s
Speed: 2400 MT/s
Configured Clock Speed: 3600 MT/s

I wonder which is the "actual" frequency of my memory? Did I overclocking success? And I tried another command, sudo lshw -short -C memory, and it shows this:

H/W path         Device        Class          Description
=========================================================
/0/0                           memory         64KiB BIOS
/0/1b                          memory         System Memory
/0/1b/0                        memory         8GiB DIMM DDR4 Synchronous 2400 MHz (0.4 ns)
/0/1b/1                        memory         8GiB DIMM DDR4 Synchronous 2400 MHz (0.4 ns)
/0/1b/2                        memory         8GiB DIMM DDR4 Synchronous 2400 MHz (0.4 ns)
/0/1b/3                        memory         8GiB DIMM DDR4 Synchronous 2400 MHz (0.4 ns)
/0/20                          memory         System Memory
/0/20/0                        memory         8GiB DIMM DDR4 Synchronous 2400 MHz (0.4 ns)
/0/20/1                        memory         8GiB DIMM DDR4 Synchronous 2400 MHz (0.4 ns)
/0/20/2                        memory         8GiB DIMM DDR4 Synchronous 2400 MHz (0.4 ns)
/0/20/3                        memory         8GiB DIMM DDR4 Synchronous 2400 MHz (0.4 ns)
/0/33                          memory         768KiB L1 cache
/0/34                          memory         12MiB L2 cache
/0/35                          memory         19MiB L3 cache
/0/1                           memory
/0/3                           memory
/0/100/1f.2                    memory         Memory controller

It just let me more confusing. Dose overclocking independent with OS? Or I should add some payload to let memory speed up? Can you give me some advice? Thank you!

overclocking ram 18.04 dmidecode

1 Answers

  1. Best Answer

    The only component in your computer that knows about the overclocking is BIOS. dmidecode retrieves its data from BIOS, which tells you that the DIMMs have a nominal speed of 2400 MT/s but are configured to run at 3600 MT/s.

    lshw prints the data that the components report themselves. Since the DIMMs don't know they are overclocked, they report their nominal speed.

    Therefore, I'd say the DIMMs are overclocked.

    There is a Q&A over at serverfault regarding benchmarking RAM. I'm not sure whether the answers provide reliable results, though.

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