Using an unmatched pair of Dual 16GB kits: a problem?

[c3k]

I've got a 6700k in a Gigabyte z170 UD5 (See sig.)

My RAM is G.Skill F4-2400C-15D-32GVR; http://www.gskill.com/en/product/f4-2400c15d-32gvr

Each stick is 16GB. Each kit has 2x 16GB sticks, for 32GB total capacity...per kit.

I know it's recommended to use matched sticks for quad, but I had to stagger my buy, so I bought two of these kits, for a total of 4x 16GB sticks or 64GB total. The kits have identical specs (the same exact sku).

I've tested it with Memtest64+ and some other tests. It -seems- okay, but now a debug program for some software is showing that I've got some floating point math errors.

My rig has been at stock speeds (XMP profile for RAM, default speeds for cpu and gpu), and volts.

Can this memory be causing the floating point errors?

Thanks,
Ken

 

[dasa]

the kits work together so its probably not a matching problem
if it is due to the extra ram it will be the difficulty the memory controller is having with 4 sticks on that mb
try increasing vccio and the system agent voltages to around 1.2-1.25v for a test to see if it helps if so a lower value may also be stable

hci memtest is good for finding errors related to ram\cache\memory controller but i dont know how you will go with getting it to use anywhere near 64g
you need to open it once for every cpu thread

if you want to know if the memory is the reason for the floating point errors remove the old sticks still have the errors? then put the old sticks back in and remove the new

this google app for linux is the quickest way i have found to test for ram related instability
but it will probably not find problems related to the memory controller struggling
stressapptest - Linux Mint Community

 

[c3k]

dasa,

Thanks. I've swapped sticks around (A1+A2 only; then B1+B2 only; then only A1; only A2; only B1; only B2). At this point, describing my issue (cpu failing the intel diagnostic test), intel is offering and RMA on the processor.

I'll see if that fixes it.

Meantime, I'll hit that link and run those tests.

Thanks!!
Ken

 

[drescherjm]

XMP profile for RAM

That could have been the problem. I mean XMP means overclocking your IMC and usually your ram as well.

An RMA may fix that by you receiving a CPU with a better IMC.

 

[c3k]

That could have been the problem. I mean XMP means overclocking your IMC and usually your ram as well.

An RMA may fix that by you receiving a CPU with a better IMC.

Well, to assuage any guilty feelings I may have, I've run the IPDT (Intel Diagnostic Processor Tool) with the ram at default values (non XMP). It only took 2 loops for a floating point error to fail the test. (Sometimes it takes up to 180 loops.)

Next, I'll remove one pair and try again...and then swap pairs and channels and retry.

Ken

 

[c3k]

^^^

And complete.

- Default memory settings, with all 4 sticks (64GB)...FAIL

- Default memory settings, with one pair, channel A...FAIL

- Default memory settings, with other pair, channel B...FAIL

Between the above results and my memtest86 and memtest86+ tests, I'm pretty confident it's either the mobo or the cpu, not the ram.