different RAM; Do I need to manually key in ALL the memory timings?

cloneman · September 28, 2021

I'm using 2 matched pairs of different brand ram.

It's DDR3 and they both support 1866Mhz 10-11-10-30 @ 1.5v.
One of the kits doesn't support XMP so I can't use that I have to key in the values manually.

In MSI's settings (z87 g45), I've keyed in those 4 memory timings, (CL-RCD-RP-RAS) but I haven't touched all the other timings (RC-RFC-RRD-WR-WTR-RTP-FAW).

Do I have to manually put those in for each pair of dimms? I've set my ram to "Unlink" so that I can put in different settings per channel, if needed.

This is what AIDA64 Says:

Patriot (XMP)

@ 933 MHz 10-11-10-30 (CL-RCD-RP-RAS) / 45-300-3-6-15-8-8-32-10 (RC-RFC-CR-RRD-WR-WTR-RTP-FAW-WCL)

Kingston (non-xmp)

@ 933 MHz 10-11-10-30 (CL-RCD-RP-RAS) / 42-243-5-15-8-8-26 (RC-RFC-RRD-WR-WTR-RTP-FAW)

If I do it wrong, how quickly will memtest fail? Is this something that would be immediately noticed?

aDoomGuy · September 28, 2021

This is the first time I've heard of a PC with different RAM timings for its DIMMs.. AFAIK the faster DIMM should use the timings of the slower one. If you don't get it stable try that.

As for how quickly memtest fails... depends on how unstable your RAM is. Maybe immidiately maybe after a while.

mariushm · September 28, 2021

The motherboard / bios should list the default timings it's going to use.

Use the more conservative timings, mix of both... also pay attention that some are missing from kingston.. use the ones from Patriot for those... and if you have errors, try increasing those values by 1.

Patriot (XMP)

@ 933 MHz    10	11	10	30  (CL	RCD	RP	RAS) / 

RC	RFC	CR	RRD	WR	WTR	RTP	FAW	WCL
45	300	3	6	15	8	8	32	10

Kingston (non	xmp)

@ 933 MHz    10	11	10	30  (CL	RCD	RP	RAS) / 

RC	RFC	CR	RRD	WR	WTR	RTP	FAW	WCL
42	243	?	5	15	8	8	26	?


So use more conservative from both:

RC	RFC	CR	RRD	WR	WTR	RTP	FAW	WCL
45	300	3	6	15	8	8	32	10

These will probably be conservative, most likely the memory sticks would run with tighter timings but usually the manufacturers (Kingston, Patriot) will leave some room just in case they have a harder time binning individual memory chips and they have to resort to slightly poorer quality chips to satisfy demand for certain sticks at some moments.

You could also try raising the voltage to 1.51v ... it's a minimal voltage increase, the ram won't care.