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#1 Z87-G45 Memory Placement

Posted: Sun Apr 03, 2016 6:52 pm
by leecarver
I picked up two sticks of 8GB (16GB total) DDR3 to add to my system that already has 8GB in it, but is always woefully short on resources. Originally, I had the the two 4GB sticks in DIMM slots 2 and 4, but now I'm not sure how to place the two new sticks. I tried placing the two 8s in DIMM 2 and 4 and the two 4s in DIMM 1 and 3. However, when I booted my computer, I couldn't get a signal to my monitor. I took out the two 4s and PRESTO, working system. I reinserted them and it worked for a while, but when I woke up this morning it was back to no signal. I took out the two 4s again and everything works. Should I be putting the two 8s in DIMM 3 and 4 and the two 4s in DIMM 1 and 2? I can't find a clear answer, even in the manual (https://us.msi.com/Motherboard/support/ ... own-manual).

Additionally, my Cooler Master Hyper 212 fan will be sitting on top of one of the two 4s if I do this. The heatsink on the memory is exposed, but the plastic of the fan on the heatsink for the CPU sits directly on top of its edge. Is this going to be problematic?

#2 Re: Z87-G45 Memory Placement

Posted: Sun Apr 03, 2016 9:59 pm
by scole of TSBT
What are the part numbers for each type of DIMM?

#3 Re: Z87-G45 Memory Placement

Posted: Mon Apr 04, 2016 2:38 am
by leecarver
They're both G.Skill Ripsaws. One is the F3-12800CL10D-16GBXL (CL-10-10-10-30) [2x8] and the other is F3-12800CL9D-8GBXL (CL-9-9-9-24) [2x4]. My presumption would be that considering the memory is from the same line and everything, that they should be able to work together, but I know with memory that's not always the case.

#4 Re: Z87-G45 Memory Placement

Posted: Mon Apr 04, 2016 4:07 am
by Alez
First thing i would try is to remove the 4 GB sticks and replace them with only the 2 x 8GB sticks in slots 2 and 4. Run that and see if the system is stable. You already know that the 4 GB sticks are good, so test the 8 GB ones before figuring out if it's a issue with the mixed types or not. It shouldn't be really as I have systems that have different sized memory modules and they work fine, with the exception of xeon server systems which usually must be matched.

#5 Re: Z87-G45 Memory Placement

Posted: Mon Apr 04, 2016 11:00 am
by scole of TSBT
The 4GB DIMMs are 1600Mhz and the 8GB DIMMs are only 1333Mhz. Might not like that. I've never mixed DIMMs with different speed specs.

#6 Re: Z87-G45 Memory Placement

Posted: Mon Apr 04, 2016 12:51 pm
by leecarver
Alez wrote:First thing i would try is to remove the 4 GB sticks and replace them with only the 2 x 8GB sticks in slots 2 and 4. Run that and see if the system is stable. You already know that the 4 GB sticks are good, so test the 8 GB ones before figuring out if it's a issue with the mixed types or not. It shouldn't be really as I have systems that have different sized memory modules and they work fine, with the exception of xeon server systems which usually must be matched.
Right now, I'm running the 2x8s by themselves and everything seems to be working just fine.
scole250 wrote:The 4GB DIMMs are 1600Mhz and the 8GB DIMMs are only 1333Mhz. Might not like that. I've never mixed DIMMs with different speed specs.
Where do you find that the 8s are 1333Mhz? Both sets should be 1600Mhz.

#7 Re: Z87-G45 Memory Placement

Posted: Mon Apr 04, 2016 1:09 pm
by scole of TSBT
This is the spec for the 4GB DIMMs....http://www.gskill.com/en/product/f3-12800cl9d-8gbxl
The tested speed and SPD speed are both 1600Mhz.

This is the spec for the 8GB DIMMs....http://www.gskill.com/en/product/f3-12800cl10d-16gbxl
The tested speed is 1600Mhz, but the SPD speed is only 1333Mhz. Tested speed means you can manually clock it to 1600Mhz, but the stock speed is 1333Mhz. At least that is what I understand Tested and SPD speeds mean. Run just the 8Gb DIMMs in it and see what CPU-Z says they're running at.

See if you can manually clock them to 1600Mhz in the BIOS or downclock the 4GB DIMMs to 1333Mhz.

#8 Re: Z87-G45 Memory Placement

Posted: Mon Apr 04, 2016 1:49 pm
by leecarver
scole250 wrote:This is the spec for the 8GB DIMMs....http://www.gskill.com/en/product/f3-12800cl10d-16gbxl
The tested speed is 1600Mhz, but the SPD speed is only 1333Mhz.
Ahhhh... That could certainly be it. I saw some mention of that in comments as I was doing some research. I'll try it out when I get home. Is it better, in your opinion, to speed up the 2x8s or bring the 2x4s down?

Grazie!

#9 Re: Z87-G45 Memory Placement

Posted: Mon Apr 04, 2016 2:29 pm
by scole of TSBT
I've never overclocked memory so I'm not sure, but to keep from taking a little bit of a hit on the memory performance try it overclocking the 8GB first. If it acts flaky, try downclocking the 4GB.

#10 Re: Z87-G45 Memory Placement

Posted: Wed Apr 06, 2016 4:38 am
by Alez
If you are lucky there should be an option to auto clock the mem in bios.
Downclocking should always work. Overclocking might cause the system to be unstable.
At least if you downclock then the increased memory capacity, less transfer to HDD etc should more than make up for any lose of speed.

#11 Re: Z87-G45 Memory Placement

Posted: Wed Apr 06, 2016 10:25 am
by scole of TSBT
I just added 2x 4GB 1600Mhz DIMMs to a system that had 2x 4GB 1333Mhz DIMMs in it and it didn't blink. It just downclocked all to 1333Mhz automatically. Maybe a difference in BIOS?

#12 Re: Z87-G45 Memory Placement

Posted: Wed Apr 06, 2016 1:37 pm
by leecarver
Just a quick update: I left the 2x8s in the system and enabled XMP in the MSI BIOS. No problems so far, no unexpected shutdowns. I did some digging on Tom's and posted my question there and the only response I got back was that it wouldn't work and to just leave in the 2x8s.

However, I'm still optimistic they should work together - I just don't want to damage anything in the process. I've found an article that walks through the process of manually downclocking (http://www.overclock3d.net/articles/mem ... _voltage/1). It seems like I'll need to pull the 2x8s out, put back in the 2x4s, downclock them, and then reinsert the 2x8s.

Scole - curious, how were you able to do it automatically? What BIOS/Board are you using?

#13 Re: Z87-G45 Memory Placement

Posted: Wed Apr 06, 2016 2:04 pm
by scole of TSBT
mobo is a MSI Z77A-GD65 https://us.msi.com/Motherboard/Z77AGD65 ... o-overview

It had 2x 4GB 1333Mhz DIMMS already. I didn't change anything. I just popped the 2x 4GB 1600Mhz DIMMS in the other 2 slots and it booted right up and has run without any problems. I didn't realize it had te 1333Mhz DIMMS in it already either. That's why I bought the 1600Mhz DIMMs. After it booted up I started checking things and noticed it reported the memory speed as 1333Mhz, checked and realized what had happened. Guess I got lucky.

#14 Re: Z87-G45 Memory Placement

Posted: Wed Apr 06, 2016 4:22 pm
by leecarver
Interesting.

I'm wondering if because XMP is on and the 2x8s are now running at 1600Mhz (theoretically) if I pop the 2x4s in, if it'll run without a problem.

Guess this will be a week of trial and errors.

#15 Re: Z87-G45 Memory Placement

Posted: Wed Apr 06, 2016 4:22 pm
by leecarver
Interesting.

I'm wondering if because XMP is on and the 2x8s are now running at 1600Mhz (theoretically) if I pop the 2x4s in, if it'll run without a problem.

Guess this will be a week of trial and errors.

#16 Re: Z87-G45 Memory Placement

Posted: Mon Apr 11, 2016 2:13 pm
by leecarver
Another update: After running the 2x8s stable for quite some time, I put the 2x4s into the system on Sunday. The system booted up just fine, so I shut it down, went into BIOS and enabled XMP again. Rebooted and the system was still running as intended. Let it run all night with BOINC going in the background and it's still going strong.

I'm not a huge fan of the heatsink/memory placement right now, but I haven't seen much change in the temperatures (running in the low 30Cs when not under load, averaging around 55-56C while running two instances of POGS and 1 instance of GPUGrid). I think I'll try running this until it goes unstable. If it refuses to boot again, I'll just pull the 2x4s and go with the 16GB.

Thanks for all the input!

#17 Re: Z87-G45 Memory Placement

Posted: Mon Apr 11, 2016 2:58 pm
by scole of TSBT
What does CPU-Z report the frequency of each DIMM as, under the SPD tab?

#18 Re: Z87-G45 Memory Placement

Posted: Mon Apr 11, 2016 3:51 pm
by leecarver
I'm not sure which frequency to give you as there are four of them listed for each slot (JEDEC #4 / JEDEC #5 / JEDEC #6 / XMP-1600).

Slot #1 (4GB): 685 / 761 / 800 / 800
Slot #2 (8GB): 609 / 666 / 666 / 800
Slot #3 (4GB): 685 / 761 / 800 / 800
Slot #4 (8GB): 609 / 666 / 666 / 800

#19 Re: Z87-G45 Memory Placement

Posted: Mon Apr 11, 2016 6:43 pm
by scole of TSBT
Not sure SPD was the right tab for info now. How about the DRAM frequency under the memory tab?

#20 Re: Z87-G45 Memory Placement

Posted: Mon Apr 11, 2016 6:56 pm
by leecarver
DRAM Frequency fluctuates between 799.9 and 800.1 MHz.

#21 Re: Z87-G45 Memory Placement

Posted: Mon Apr 11, 2016 7:13 pm
by scole of TSBT
Looks like it's all running at 1600Mhz then.

In case anyone was curious why it's reported at 800Mhz instead of 1600Mhz, like me, this is from tomshardware.com....

"DDR" means Double Data Rate".

CPU-Z reports the raw DRAM frequency x 2 = effective data rate.

What you're seeing is simply a difference in nomenclature.

"DRAM Frequency" in CPU-Z means one thing; "DRAM Frequency" in your BIOS means TWICE that!

If you were viewing the memory clock as a sine wave, you would have 1 peak and 1 trough for every cycle: that's how DDR works: it transmits data once for each rise in voltage and once again for every drop in voltage.

Of course, the sine wave analogy is "analog" --whereas DRAM is digital -- more like a "step function" as opposed to a smooth undulating "wave".

Because CPU-Z has become a de facto standard, get used to the tables produced with the "Memory" and "SPD" tabs in that fine program.

#22 Re: Z87-G45 Memory Placement

Posted: Mon Apr 11, 2016 8:58 pm
by leecarver
Thanks for the reply, scole! I'm going to keep my fingers cross these two will play nice with each other going forward.

And am certainly glad to have CPU-Z as a new tool to understand and utilize.