[SOLVED] CPU-Z memory tab timings differ from SPD timings tables for both memory slots

Sep 30, 2020
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I recently purchased a desktop from a student that was eager to sell as he was due to leave the UK the next day... I got the following setup for just £40:

Tower/Case: unknown brand (and very flimsy)
PSU: CIT M-500MB 500W micro ATX
Mobo: Gigabyte GA-H81-M-S2H
CPU: Intel Core i5-4460
Graphics Card: ASUS Dual GeForce GTX-1060-O3G
Storage: SSD Crucial BX500 2.5" Internal Sata 3
RAM: 16GB DDR3
Kingston KHX1600C10D3/8G - 8GB DDR3
Kingston 99U5403-465.A00LF - 8GB DDR3
Also included 1080p ASUS screen and cooler master keyboard... not a bad deal in my opinion.

Anyways, moving on to the point of this post:

One of the RAM modules is PC3-10700 (667 MHz) and the other is PC3-12800J (800MHz) - I quoted from CPU-Z SPD tab.
I'm not concerned about the different frequency values, I'm aware that the system would default to the lower of the two (and it does - CPU-Z memory tab confirms it).
What I am concerned about are the latency timings...
Please can someone tell me if I am wrong in my understanding that the Memory tab timings should match the SPD tab timings for all slots used? - in other words, if I mixed two RAM modules with different latency spec's, the system should set the memory timings so that they match JEDECs for both modules.
Memory tab shows 9 - 9 - 9 - 25
SPD tab slot 1 shows 9 - 9 - 9 - 27 (closest match)
SPD tab slot 3 shows 9 - 9 - 9 - 24 (closest match)

Can anyone tell me if I should expect any performance / stability issues with this setup?

Thanks in advance!
 
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Solution
in other words, if I mixed two RAM modules with different latency spec's, the system should set the memory timings so that they match JEDECs for both modules.

No, not necessarily.
That's why mixing/matching memory modules can be problematic on occassion.

If every system could 'force' JEDEC standard speeds/timings to something all kits of memory could run, then mixing & matching would never be a problem.

Can anyone tell me if I should expect any performance / stability issues with this setup?

Nobody can say definitively.
You can likely manually configure timings (to the loosest of the two) in the BIOS on a DIMM by DIMM basis.

Barty1884

Retired Moderator
in other words, if I mixed two RAM modules with different latency spec's, the system should set the memory timings so that they match JEDECs for both modules.

No, not necessarily.
That's why mixing/matching memory modules can be problematic on occassion.

If every system could 'force' JEDEC standard speeds/timings to something all kits of memory could run, then mixing & matching would never be a problem.

Can anyone tell me if I should expect any performance / stability issues with this setup?

Nobody can say definitively.
You can likely manually configure timings (to the loosest of the two) in the BIOS on a DIMM by DIMM basis.
 
Solution
Sep 30, 2020
3
0
10
No, not necessarily.
That's why mixing/matching memory modules can be problematic on occassion.

If every system could 'force' JEDEC standard speeds/timings to something all kits of memory could run, then mixing & matching would never be a problem.

Thanks for the swift reply!

I thought there was something "iffy" about this setup. I guess it's possible that I could encounter problems if I leave the values as they are...

Nobody can say definitively.
You can likely manually configure timings (to the loosest of the two) in the BIOS on a DIMM by DIMM basis.

I will have a look in the BIOS and see if there is something I can do to make the values suit both RAM modules. If not, I guess I'm probably best off replacing one of the two modules so that I can properly match the all spec's in this dual channel configuration.

Thanks again for your response.
 

Barty1884

Retired Moderator
I will have a look in the BIOS and see if there is something I can do to make the values suit both RAM modules. If not, I guess I'm probably best off replacing one of the two modules so that I can properly match the all spec's in this dual channel configuration.

You're probably best replacing both if you run into issues.
Even if you watch speed & primary timings, you typically can't do too much with secondary/tertiary timings, which could still present issues if they're not a matching retail kit.