Question Old RAM and new RAM together blue screen even though they have apparently the same specs

halfbeing

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Sep 2, 2014
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I bought a pair of second-hand DDR-3 sticks to go alongside my two existing RAM sticks, but I get blue screens within a minute or two when I use them together, even though they have the same basic specs. However, the computer runs fine when either pair is installed without the other pair. What have I got wrong?

I have a problem with my motherboard which means that memtest86+ freezes two seconds after starting a scan, however it was able to identify the RAM in both cases and confirm that the basic specs (4GB per stick, 1600 MHz, 9-9-9-24) were the same.

memtest86+ names the RAM as "DDR3-1600 A-DATA DDR3 1600G XMP" (the new memory) and "DDR3-1600 Crucial BLS4G3D1609DS1S00 XMP" (my existing memory) respectively.

The motherboard is an ASUS Sabertooth 990FX (1st generation). I have not enabled overclocking in any way.

There is something anomalous about the actual speeds reported. Memtest86+ reports the Crucial memory as running at 652 MHz (DDR3 1305) — a lot less than its nominal speed. But the Crucial memory it reports as running at 783 MHz (DDR3-1566).

I also looked at both pairs of memory separately in CPU-Z. It reports 9-9-9-24, but there are discrepancies with other numbers. The A-DATA memory it says is running at 668.9 MHz, whereas the Crucial memory it reports as running at 802.7 MHz, which is close to the nominal speed. (When I have run CPU-Z in the past, it has always reported speeds for the Crucial memory of between 800 and 803 MHz.

There is also a discrepancy, according to CPU-Z with the Bank Cycle Time. For the A-DATA memory it is 33 clocks, whereas for the Crucial memory it is 37 clocks.

So what have I got wrong? Why won't the memory work together? How can I make sure that next time I get memory which is compatible with my existing memory?
 

Math Geek

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this is why it is recommended to buy a matched set and not try to mix and match ram. it works sometimes and others it will not like you are seeing.

you are also populating all 4 slots which causes problems for many motherboards. look at the mobo manual for the various ram it can support. often when all 4 slots are populated you can't get faster speeds or will only work with single bank and not dual bank sticks and other possible issues.

i know you tried to get "the same specs" for the new set but in the end they are clearly not the same internally and are slightly off. try turning off xmp and running them at slow default speeds and see if that works.

in the end, most likely you will want to buy a matched set that has as much ram as you need, preferably in 2 sticks and not 4.
 
Show screenshots from CPU-Z memory and spd sections,
when booted with kit #1 and​
when booted with kit #2.​
(upload to imgur.com and post link)

Generally mixing multiple kits together requires tinkering with memory settings - latencies, frequency, ddr voltage.
Sometimes different kits may refuse to work together at all.
 

halfbeing

Honorable
Sep 2, 2014
31
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Show screenshots from CPU-Z memory and spd sections,
when booted with kit #1 and​
when booted with kit #2.​
(upload to imgur.com and post link)

Generally mixing multiple kits together requires tinkering with memory settings - latencies, frequency, ddr voltage.
Sometimes different kits may refuse to work together at all.
Thanks for replying. Thanks both of you for replying.

Here's the screenshots.
 
Ok.
First - set DDR voltage to 1.65V.
Set command rate to 2T.

Next try settings:
1333mhz, 9-9-9-24 - this should work.

If it works, then you can go further. Try:
1600mhz 11-9-9-24 - this would be ok result.

You can try tightening settings even more:
1600mhz 10-9-9-24,
1600mhz 9-9-9-24.

At some point it will probably stop working. Then reset BIOS and return to previous settings
 
Reactions: halfbeing

halfbeing

Honorable
Sep 2, 2014
31
1
10,545
1
Ok.
First - set DDR voltage to 1.65V.
Set command rate to 2T.

Next try settings:
1333mhz, 9-9-9-24 - this should work.

If it works, then you can go further. Try:
1600mhz 11-9-9-24 - this would be ok result.

You can try tightening settings even more:
1600mhz 10-9-9-24,
1600mhz 9-9-9-24.

At some point it will probably stop working. Then reset BIOS and return to previous settings
Thanks ever so much! I've managed to get it to 1600MHz 9-9-9-24 and it seems stable.
 
Reactions: maestro0428

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