Ddr3 dual rank- Both sticks fine when solo installed , dual channel fail even 800mhz loose timings

[ddr3guy]

Hi guys
Got z77-a , F3-12800CL9D-8GBXL (dual rank) , and i5 2500

Testmem5 anta777 and 1usmus_v3 find no error with both sticks when they installed solo , but when I try both sticks w dual channel 1usmus_v3 always find +15 error even at 800 mhz
Can it be cpu dont support 2x dual rank ? If so will 2500k might support?
Does testmem5 ok with ddr3?

I tried setting vcore to pretty high too
Tried another mobo p8b75 , same thing

Found similar: https://www.techpowerup.com/forums/...e-bsod-but-single-ram-is-running-fine.167856/
" The broken stick works fine on its own since the strain put on the memory bus is lower with only one stick, but with more RAM installed the workload increases and the faulty stick can't handle it "

 

[ir_cow]

Can it be cpu dont support dual ranks ? If so will 2500k might support?

Hmmm. Good question. I've only seen dual-rank DDR3 as enterprise stuff, but since it boots, it must be supported.

Does testmem5 ok with ddr3?

Yes

 

[Massdeth]

@ddr3guy Do you mean dual rank or dual channel?!?! Those are two very different things and sound like you are asking more about dual channel than rank. I have a set of those same sticks but cas 8 and theyy arent dual rank and run fine at stock on a EVGA p67 ftw and a i5 2500k. Did you try raising voltage a tad on cpu and ram, put the command rate to 2 instead of 1 for the ram timings? A tad on the voltaage, too much will give you the same result as too little. Did you check that no pins are off a little, or broken/bent in the socket of the cpu?

 

[ddr3guy]

@ddr3guy Do you mean dual rank or dual channel?!?! Those are two very different things and sound like you are asking more about dual channel than rank. I have a set of those same sticks but cas 8 and theyy arent dual rank and run fine at stock on a EVGA p67 ftw and a i5 2500k. Did you try raising voltage a tad on cpu and ram, put the command rate to 2 instead of 1 for the ram timings? A tad on the voltaage, too much will give you the same result as too little. Did you check that no pins are off a little, or broken/bent in the socket of the cpu?

Rams are dual rank , 8+8 chips on front and back per stick , and cpu-z reports dual rank , your appear to be single rank
Errors occurs when they operate as dual channel , but they both fine when installed by 1 at the time on all slots
Cr always set to 2n , I didnt tried voltage bump cuz Im testing them at very low speed , but I will then
Cpu socket seems okay , did brushing too

Now I tried different cpu (Pentium g860) at first errors occured
-Then changed cpu cooler , no errors
-Then tried 2500 with other cooler , error
-Then tried pentium again with "other" cooler , again error ( pff)


But these were with 1usmus_v3 20min test only , so maybe by luck didnt get errors on that 1 time , idk
Now I will try to seat cooler very loose

 

[ddr3guy]

Hmmm. Good question. I've only seen dual-rank DDR3 as enterprise stuff, but since it boots, it must be supported.


Yes

Yeah , tried disabling extra dimms on bios too , still unstable
As I read extra chips physical existence alone will reduce signal integrity
Putting this for future readers

 

[ddr3guy]

Noticed a behaviour:

Cpu clocks drops to 200 on 2500 ,
and to 187 on Pentium
Even tho c-states disabled , speedstep disabled , os set high performance , and cpu ratio set manual
Under heay load they dont drop , but on idle or while chrome youtube video plays vs they drop
This behaviour occurs on both motherboards ( z77 and p8b75)
And with both single and dual channel setup

They should not ?

My psu is good , removed it from 12th gen system which was stable and its rm750x

Oh and important question :
Since I got lots of errors , can os corruption make testmem5 unreliable in time ?

Edit: Tried in a compeletly different system , still errors , prolly kit is defected