Advice/help requested w/ 8350 + Sabertooth 990FX 2.0 + 32 GB 2400 MHz

[michael-matthew]

AMD FX 8350
ASUS Sabertooth 990FX 2.0
Corsair Vengeance Pro (CMY32GX3M4A2400C11R) -- 32 GB (4 x 8 GB) 2400 MHz 1.65V 11-13-13-31
Corsair HX850i -- 850w Modular
2x AMD R9 270 w/ 2 GB each
Swiftech H20-220 Ultima Water Cooling Kit


I'd like help with 2 things, in order of importance to me:

1. Stabilizing RAM at 1600 or 1866 MHz
2. Stabilizing CPU at 4.6 or 4.7 GHz

I know the CPU will do 4.6 or 4.7 as I have had it up there before, nearly stable. Temps were the limiting factor before I had put the w/c kit in. But I would like to work on the RAM first.

I realize that 32 GB is a large amount, and the AMD CPUs have weak IMCs. Had to bump up CPU/NB to 1.225v and change to 2T, just to get it to do 1 pass of Memtest86+ at 1866 without errors... Currently CPU/NB is at 1.250v to fix some issues that popped up - NIC flakiness and the clipboard (copy & paste) not working in a VM. I'm looking for advice on settings to pick, or expected value of CPU/NB, for an overnight run of Memtest86+ at 1866.

I will post more settings and the CPU-Z images once I figure out what the forum likes.



I disabled Turbo, C6, CnQ, APM, C1E and anything else power/throtting related in the BIOS.

 

[Mr.Scott]

Much more CPU/NB volts. 1.3-1.35.

 

[michael-matthew]

1.3-1.35 at 1866? Thanks, will do.

Timings look okay? I picked the ones from the 2400 profile to be on the safe side.

For reference, using the ASUS D.O.C.P. it will POST with 1866, 2000, and 2133 but not beyond that.

 

[trents]

The FX CPUs will usually run RAM at 1866 mhz without adding voltage to the CPU/NB. If you want to run the RAM at higher frequencies you will likely need to add volts to the CPU/NB which is a component having to do with the memory controller and one that is not as strong as on the Intel enthusiast level CPUs. You may find it just won't do 2400.

 

[ssjwizard]

FX memory controller kinda leaves alot of to be desired above 2000mhz. I usually run my memory around 1900 for day to day and push it up to around 2100-2200 for benching and it takes ALOT of extra voltage to pull it off even though the memory is rated for it.

 

[michael-matthew]

Hmm...so CPU/NB at 1.3-1.35v for 1866 or just when going beyond 2000?

Seems like I'm getting conflicting advice from different people.

Thanks for the feedback though. I'm getting a better understanding of how this works, little by little.

 

[Mr.Scott]

I never mentioned speed.
I'm saying 1.3-1.35v CPU/NB just to run 32 gig at 1866.
You may never get faster than that with that much ram.
AMD was never rated for more than 1866. People that can go faster were just lucky on the draw.

 

[ShrimpBrime]

Memory voltage to 1.650v - 1.700v and increase the reference clock to achieve 4.6ghz from 4.5ghz. This will increase the memory frequency higher, as well as NB and HT. but just a little at a time. Start with 202, 204 ect. Test each interval as needed.

Be sure to actively cool VRM and memory with a fan.

Run CPU LLC to ultra high to stabilize CPU voltage.

 

[caddi daddi]

is this a stable 4.5 cpu clock???

 

[Mandrake4565]

Much more CPU/NB volts. 1.3-1.35.

Agreed! I needed 1.3875 Cpu Nb v to get my ram stable at or above 1866 on my 8350 and that was with only 2 x 4 gb.

 

[Mr.Scott]

Agreed! I needed 1.3875 Cpu Nb v to get my ram stable at or above 1866 on my 8350 and that was with only 2 x 4 gb.

Me too.
I answer from personal experiences, not educated guess.

 

[MaddMutt]

^ I had this problem POP UP on me today, while benching for the Comp IV Div. I only needed 3 bench runs (CineBench 15, Catzilla 720P, and FS Extreme) but spent 5+ hours of playing around. I had more BSOD's (it seemed like every 5 minutes) than I have ever seen. I now know why as my CPU NB was set to auto on 2 x 2GB 2133 @ 9-10-9-24 1T. I suspected the RAM, so I switch out the 2 X 2GB's for my backup set of 2 X 4GB 2133 @ 9-11-10-28 1T. I still had the BSOD's with the backup set so I was kinda at a loss on what was wrong.

 

[Mr.Scott]

Whip the speed down to 1800 or so and tighten the timings a little.
I haven't subbed in that division yet. Soon though.

 

[ShrimpBrime]

Much more CPU/NB volts. 1.3-1.35.

That's all you guys run? Gosh I gotta back down that 1.55v thing I got going on..... eek.

 

[Mr.Scott]

LOL. You're a different animal Jon.
AMD says 1.45v is the safe limit. You push that limit on everything you own.
I know and see why.
You are a true extremist.

 

[Mandrake4565]

That's all you guys run? Gosh I gotta back down that 1.55v thing I got going on..... eek.

For my daily Oc yeah. I worked pretty hard getting my 8350 to pass 2 hours of prime blend once I put my 1866 G Skill snipers in, I had been previously running 1600 sticks. The Snipers threw my setup for a loop, went through 2 Rma's thinking the sticks were bad but turned out I wasn't giving the Cpu Nb enough voltage. So for a daily Oc 1.3875 was what I needed to pass 2 hours of blend. Now pushing to extremes that's a whole different ball game, I have no qualms about running the Cpu Nb high when running hard. Just don't see any reason to when running it a daily Oc.

 

[michael-matthew]

I never mentioned speed.
I'm saying 1.3-1.35v CPU/NB just to run 32 gig at 1866.
You may never get faster than that with that much ram.
AMD was never rated for more than 1866. People that can go faster were just lucky on the draw.

Thanks!

Actually 32 GB 1866 at 1.3 CPU/NB fixed a few issues (that I had chalked up to software bugs) I experienced when running 16 GB 1600 at stock (1.1625) CPU/NB.

I don't think I'll go beyond 1866 as from what I've heard there's not much benefit on this platform.

 

[michael-matthew]

is this a stable 4.5 cpu clock???

I believe so. LLC is set to Ultra High to keep it from dipping under load. I'll have to play around with it a bit more at 4.5 and also get some numbers at 4.6 and 4.7 before asking for help getting it stable at 4.6 or 4.7 for daily use.

When I checked the RAM, CPU was at stock to isolate failures.

 

[trents]

Passing 2hr. of Prime95 blend is sort of the agreed upon standard on the forum for considering an overclocked system stable for daily use.

 

[michael-matthew]

Passing 2hr. of Prime95 blend is sort of the agreed upon standard on the forum for considering an overclocked system stable for daily use.

4.5 GHz at 1.428v (in CPU-Z) passed 3.5 hours of Prime95 blend. Max temp was 56 C, motherboard temp (not sure if socket or VRM) was 70 C.

Given this, how likely would it be for me to reach 4.6 or 4.7 GHz with <= 1.5v and what would be good ballpark voltages for trying at those speeds?

Since I'm watercooling, I'll look into 3D printing a duct to force my 140mm case exhaust fan to draw air from the VRM heatsink.