Anyone have a fast X79 system with lots of RAM?

JonJ678

JonJ678

JonJ678

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Looking around forums suggests that a stable overclocked 3930k will reach somewhere between 4 and 5ghz, where 5ghz is unusual and 4 would be very poor. Average seems to be around 4.5.

What is more difficult to judge is how the system reacts to having more ram. I spent a lot of time messing around with a X58 system with all the slots populated - it did not go as high with 12gb of ram as it did with 6gb.

So is anyone here running a X79 system with all the slots populated? If so, how much harder does that make the overclock?

Thanks :)

edit: the limit seems to be 64gb on the couple of boards I've looked at, so I suppose by "a lot of ram" I mean 32 or 64, since no one is likely to be using eight 2gb sticks
 
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I've got 32GB of RAM in my board, I'm running at 4.6ghz, but to be honest I still don't really know what I'm doing.

I just spent an hour playing with the settings and doing a bit of light reading to get to 4.6, and just left it at that, I will go back at some point and learn the settings more so I could potentially get a higher overclock.

I will be going for 64GB at some point, as I've got a brand new pack of 16GB of the same modules I currently have that I got for cheap, I just need to get another one for 64GB :D
 
The best person to ask is 8 Pack in his section at the top of the page.

Filling up all the slots on X79 works the same way as X58 the memory controller is on the CPU. The more memory and the more slots you have filled the harder it is to oc the CPU.

16gbs is about the optimum for X79, enough to do most things and ok to get a good o/c and high memory speed with tight timings.

Unless you have something that uses the extra memory it is best to go for 4 x 4gbs of ram.
 
What testing did it pass spoffle? That's a much better result than I was hoping for :)

That's pretty much what I was concerned about Kaapstad. Clock speed down and memory bandwidth (or is it throughput?) down as all the channels fill up. With the additional annoyance that eight slots of ram significantly reduces the range of motherboard choices. I'm sure I can use the extra ram though, my current 12gb system runs out often enough.
 
Im running a x79 UD5 with 3930K and 64GB of RAM.
Currently still working out the overclock but at the moment I have it at 4GHz (not looking to push much harder as I need fully stable system for work - still waiting to get some tweeks done via 8 Pack). The Ram is at its stock 9-9-9-24 timings @ 1600MHz and 1.5v although I may need to increase this to 1.6v.
 
JonJ678 said:
What testing did it pass spoffle? That's a much better result than I was hoping for :)

That's pretty much what I was concerned about Kaapstad. Clock speed down and memory bandwidth (or is it throughput?) down as all the channels fill up. With the additional annoyance that eight slots of ram significantly reduces the range of motherboard choices. I'm sure I can use the extra ram though, my current 12gb system runs out often enough.
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The best clocking boards are the ones with 8 Dimms slots though.

Do yo uneed above 16gb of RAM??? if you dont go 16gb with a tuned 2400mhz for performance.

I just clocked an 8 dimm populated board with CPU at 4.7 here with not to much trouble though. Dimm speed around 2133 9-11-10-28 1T.
 
I have 64gb and have a stable overclock of 4.5ghz. I'll admit i've never actually ran memtest but i do leave the machine rendering for long periods of time, just under 30 hours is the longest single one i've done since i upgraded the memory.

I went from 16gb of samsung green to my current setup, and I did have to adjust my overclock, I had it the base clock at 125 and the multi at 36, i couldnt get it to boot with the 64gb at those settings, but just changing it so the base clock was 100 and the multi to 45 and its been working great. In the end i didnt need to adjust the sa voltage, my overclock is basically just set the vcore, set the multi and thats it, all other voltages are stock, all voltages confirmed with a multimeter. For the ram i just set it to use the xmp profile. My motherboard is msi gd-65 8d, and all 8 dimms are filled, these boards had a rocky start but since they sorted the early bios issues its really been very reliable, although i do seem to need more vcore than others for the same overclock, i have no idea if thats the board or the cpu.
 
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It maybe the the fact you have full dimm population. a lot of CPU need higher Vcore VCCSA/VTT for 64gb.

What speed are your DIMMS 1600mhz ????
 
Yeah its 1600mhz, ocuk dont have it listed anymore but its Avexir Blitz. But tbh i've gone from 8gb to 16gb and now 64gb and i've always had to run a bit more vcore to get it stable, its currently 1.44v for 4.5ghz which i know is high, but i have no cooling issues with my water setup. I have as you reccomended in the past tried upping the the vccsa and vtt to around 1.15v to see if i can reduce vcore, but without any success.
 
1600mhz 64gb its not too hard actually overclocking the ram is with so much DRAM. Have you tried PLL 1.65 or even clocking on the 125 strap with higher BLK. Often these tweaks help lower Vcore.

1.44 is high 24/7.
 
nope not tried that yet was having a look at your overclocking guide the other day, although half the settings aren't available on my msi board lol.

I know its high, but temps are in the 65 degree range even after 24+ hours of solid rendering at 100% cpu usage. I've tried periodically tweaking things but ultimately I end up with instability after a few hours. Am I likely to do damage at that voltage long term? I really appreciate the extra speed for rendering.
 
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