Compatibility between 'identical' RAM kits with slightly different SKU

Brun · 26 May 2023 at 19:11

Am considering adding another 32GB to my system. Currently have 2x16GB G.Skill Trident DDR5 6000, and on first glance it appears I can buy the same again - at 25% of the price I paid about 18 months ago.

However, on closer inspection I've noticed the SKUs are slightly different. Existing is F5-6000U3636E16GX2-TZ5K, and the new stuff is F5-6000J3636F16GX2-TZ5K. Also just noticed that the timings are slightly different - CL36-36-36-76 vs CL36-36-36-96.

Any ideas if that's likely to cause issues? Seems mad that DDR5 is so 'cheap' now that buying a new 64GB kit is worth considering otherwise.

mickyflinn · 27 May 2023 at 06:05

Memory with different trimmings will default to the slower values in this case 96 compared to 76 but you can never tell if issues will arise until you try it.

I would give it a go then return it of any problems.

Troezar · 27 May 2023 at 13:04

I presume you could just manually set both kits to the same values?

Tetras · 27 May 2023 at 15:00

Brun said:
Any ideas if that's likely to cause issues? Seems mad that DDR5 is so 'cheap' now that buying a new 64GB kit is worth considering otherwise.

Unless the manufacturer specifies exactly what memory chips they use, then buying the same kit guarantees you nothing really (in terms of compatibility), unless you're aware (like buildzoid is) that particular specs imply particular chips.

According to this article Intel only guarantee 4000 for 4 single rank sticks with a 12th gen CPU, but I'd expect a later BIOS to improve your chances of better speeds than a launch bios.

exa · 28 May 2023 at 14:47

Both of those kits will use Samsung ICs- 16gbit B die, so mixing them will be fine assuming your IMC is up to it- worst case is you drop the frequency by 100Mhz or so.

Brun · 29 May 2023 at 22:26

Thanks for the replies, have ordered the other 2x16GB and will see how I get on.

Brun · 2 Jun 2023 at 21:02

All seems good. Booted straight to Windows without having to change any BIOS settings and CPU-Z is showing 3000MHz and 36-36-36-76. Expected the last of those to be 96 on account of the newer sticks, but very much doubt it makes any noticeable difference either way.

BUDFORCE · 3 Jun 2023 at 07:23

Brun said:
All seems good. Booted straight to Windows without having to change any BIOS settings and CPU-Z is showing 3000MHz and 36-36-36-76. Expected the last of those to be 96 on account of the newer sticks, but very much doubt it makes any noticeable difference either way.

I think outside of benchmarks you'll notice no difference what so ever.