Max voltage for F3-16000-8GBRM?

[mingus]

I am currently working on overclocking my F3-16000-8GBRM 2x4 kit, on an Asus M4A89TD Pro with a Thuban 1090T. This particular CPU is stable at 3.9GHz. The IMC was stable (12 hrs Prime) at 2880 CPU/NB freq with this RAM at 1600/CAS 9, and at the moment I have the RAM clocked at 1840 with 8-9-8-25-1T timings and 2760 CPU/NB freq, so far (5+ hrs) also Prime stable. The CPU/NB is at 1.35V and the NB is at 1.225V. I'm keeping HT close to stock, so it is just at 1.2V.

The RAM is set to 1.65V (stock is 1.55). My question is, what is the maximum voltage this RAM can handle?

I've seen posts elsewhere here with other F3-16000 kits clocked at 1846 with 7-8-7-24-1T timings and 1600 with 6-7-6-24-1T timings, both of which would be better than what I've done so far. I tried my kit at 1840 as it is now but with the CAS 7 timings, and the machine could not get past the post. The aforementioned 1846 user has his RAM at 1.7V, which I suspect I would also need to do to reach CAS 7. Hence my question. (So OK, I'm greedy and want the most I can get from my GSkill ).

If it matters, I have Corsair 3x40mm fan cooling on the sticks. The CPU is on Swiftech water and I've supplemented the NB passive heatsink with a Noctua fan. Under Prime sustained load, the mobo temps are 27-29c, (ambient is 26c) and the CPU temps are only at 54-57c.

Thanks in advance!

[NemesisChild]

Even though within safe operating limits, you're CPU is running hot for being cooled by water.
What is your CPU voltage set at?
And your CPU/NB votage does not need to be that high, I would only go 1.30v max.
I run my CPU/NB at 2830MHz 24/7 with only 1.275v CPU/NB voltage.

I don't see the full specs of your memory in your post, is this your set:

http://www.newegg.com/Product/Produc...82E16820231407

[mingus]

Thx very much for the reply. And, yes, that Egg url is the kit.

CPU is at 1.5V. The 1090T is spec'd at 1.475V for its rated 3.2GHz frequency. 1.5V is OK for a 3.9GHz clock; this board on Auto pulls about that voltage if Turbo (3.7GHz) is enabled. 1.5V is what I see on the overclocking forums as typically the max recommended for 24x7. I know others have gotten higher clocks with less voltage (and I've noticed that the Crosshair seems to handle voltage better than the M4A89TD even though same chipset), but that varies across individual chips - the puppy I got from the Egg becomes unstable >4GHz regardless of voltage, which is why I'm only using 3.9GHz. I just wasn't lucky.

Similarly, the CPU/NB range I've seen is 1.3-1.4V for 2600-3000, depending on timings, and that is also consistent with this bios's Auto settings. Actually, I've mostly been at 1.3V (and the NB at 1.2V), but bumped it up as I've worked to get the RAM >1800 with tighter timings. With the RAM at 1600/8 and CPU/NB Freq at 2400, or the RAM at 1840/9 and Freq at 2760, 1.3V appears to do fine.

Re the heat, this block is spec'd at ~40c core temp above inlet temp. With an ambient here of 26c (hot!) that works out to ~60c, which according to AMD is acceptable. Of course, the 54-57c I'm getting is with Prime on all cores, just for stress testing. Idle is ~28c core/~34c socket.

As far as the RAM voltage . . . ?

Thanks!

P.S. That's one helluva side fan you've got there!

[NemesisChild]

Think I read somewhere here in forums that you shouldn't go any higher than 1.70v.
Didn't mean to hijack your thread, but just wanted to share some info with you.
I have tested the 1090T and Crosshair IV to the max., so I have a good feel about voltage settings, etc.
That's a shame, I run my 1090T just over 4.0GHz with only 1.45v on a 24/7 basis.
Try raising your NB voltage to 1.3875v, it sometimes helps with CPU stability.

Also, have you tweaked your CPU and CPU/NB Load Line Calibration settings?

That 200mm side fan keeps my twin 570's in the low 70's under full (100%) GPU load.

[mingus]

Thanks for quick reply! And, naw, you didn't hijack the thread - info appreciated. I'm not surprised at how well the Crosshair has performed for you - just based on what others have reported, nothing scientific, but seems it does do better than the M4A89TD (for that matter, so does the Gigabyte counterpart, but its layout didn't work for me). I tried to get more out of my chip with lower voltage, it just wouldn't go there. I probably could do 3.7GHz (Turbo) with only 1.45V, but my prev Phenom II could do 3.8GHz and I didn't want to go backwards.

I'll try pushing the CPU/NB a tad farther as you suggest. And, good to know that the RAM voltage can be pushed a little more, too.

As far as LLC, I've fiddled with it a bit but frankly been unsure given all the rancorous debate about it. I do have the VDDA at 2.7. I'll give LLC a closer look. But unlike your Crosshair, I only have on/off/auto options - I can't actually set the percentages.

[NemesisChild]

No, not the CPU/NB voltage, the NB voltage = 1.3875v

Known fact the Thuban X6 can run at higher frequencies with lower Vcore.
Something just isn't right if you need 1.45v for only a 3.7GHz overclock.
Bet my bottom dollar it's your board and it's probably over volting like crazy.
Heck, I run my C3 955 and 965 at 3.7Ghz with only 1.3675v on my family's comps.

[mingus]

Jeez, thx for catching my mistake re your recommendation. I am a bit surprised though - IIRC the NB stock is ~1.1. Over on the OCZ forums, one of their tech's suggested 1.25 (although IIRC that was with a quad), but cautioned doing so only with active cooling - this board only has passive on the NB, which is why I modded in the Noctua above it. That said, it makes perfect sense to raise the NB voltage more as you said; I've needed to do that on prev rigs, too.

You do have me even more suspicious of the board now. I say "even more" because today when I used "Auto" to just determine what the bios would do, I noticed that at my 2760 cpu/nb freq it would have set its voltage to 1.45V, which is way too hot - and way into the red on the bios's own scale. And I'm aware as you point out that the Thubans handle voltage better. You may be right about the board - I'll definitely check this out further.

Thanks a lot - again!