How does Samsung UCCC react to voltage?

[politenessman]

i have been using bh5 and tccd for the past couple years and just got my first 2gb kit which is g.skill hz. it will run up to around 260mhz @ 3-3-6-3 but anything over that has to set @ 3-4-6-4. this is with 2.7v vdimm. i have read in a couple places that this ram runs best with very low vdimm, ie 2.55v, and a couple other places that said 2.85v is best. i just want to get started in the right direction. 1t is enabled, odd divisor is enabled, basic timings set as above,everything else is on auto. any input appreciated.

very truly yours,
politenessman

[shadowing]

Try out most voltage up to 2.9V. Over that... and who knows what happens...

[thunderstruck!]

First of all. If you are using Odd Divisor, then your hz isn't really 260mhz. It's actually lower. It's all here in this thread. http://www.xtremesystems.org/forums/showthread.php?t=95860

If you want to still use your odd multi, then disable the feature or try a new bios. I use 11/14.

Now about voltage, it varies from each set of UCCC. My set errors in memtest at 2.63v at 275, but is rock solid at 2.53v (Bios set). I suggest trying 2.5 ~ 2.9 You REALLY don't need that much voltage, but you never know. Also, active cooling is required if you want stability. You might also want to try 3-4-4-8, which is what UCCC maxes out on.

[nn_step]

UCCC actually reacts better to lower voltage than highier voltage.

[Reinvented]

UCCC actually reacts better to lower voltage than highier voltage.

QFT! It depends on your batch/serial number as well. 0601-0603 are doing quite well. I myself got a 0603, and was doing 280 1:1 @ 2.6v. No need to pump it up to 2.9 like some guy up there said (doesn't know what he's talking about).

It scales pretty well though. I'm sure I could easily squeeze out 290 if i tried a bit more, but at this point, cpu limitation.

Look around at the various threads for HZ, and get familiar with some of the basic settings.

[politenessman]

i guess i would have to remove the heat spreaders to see the batch (week?) number?

very truly yours,
politenessman

[thunderstruck!]

i guess i would have to remove the heat spreaders to see the batch (week?) number?

very truly yours,
politenessman
First 4 digits of serial # on the sticker slapped on the mem sticks.

[Dave338]

For what I've seen seems about 2,7 is best voltage for UCCCs, but as happens with TCCD some batches can react better to a bit more volts, is matter of testing. If upping 0,1v gives no better perf. or loss lower it!!

;)

salu2.

[elected]

My sticks are a bit older (bought in november) and they seem to like above than average voltage: 2.77v (2.7 + 0.03v). Older batches like more voltage perhaps? Anything below or above that isn't prime stable. I have a 120mm Nexus blowing over them. 287MHz 3-4-4-8-1T 12h prime blend stable :)

[k0nsl]

I just got a set of 2GBHS and I am having trouble getting them stable at 240/250MHz. Hope you don't mind that I post in this thread :)

I have attached a A64 Tweaker screenshot.

Perhaps somebody has experiance with these. I certainly don't. I've only run various TCCD based memory and BH5.

PS.
I am currently running 2,8V through them, so I will lower the volt on next reboot to see...
I'm pretty sure I just overlooked some setting (which can be very critical).

-k0nsl

[Eldonko]

UCCC actually reacts better to lower voltage than highier voltage./agree Mine works best with 2.65v, higher loses Mhz.

[k0nsl]

OK, I got mine (2GBHS) stable at 250MHz currently using 2,7V and changed timings. I'm very happy with this kit :)

-k0nsl

[Fission]

Has anyone out there managed CAS 2 on their UCCC? Typically tighter timings like a little more voltage regardless of the chips, but it seems that no matter what I've tried, I just gotta be happy with cas 3 and cas to ras delay of 4 for decent clocks or performance.

[k0nsl]

I don't think mine will run 2.0CAS but maybe, maybe they will run 2.5CAS. I can certainly try on my next reboot.

-k0nsl

[Deathspawner]

Yeah I never had luck with my UCCC 2GB accomplishing CAS2. My kit are from last Sept/Oct and react better to more voltage.. so I guess the production date does matter.

[nn_step]

Has anyone out there managed CAS 2 on their UCCC? Typically tighter timings like a little more voltage regardless of the chips, but it seems that no matter what I've tried, I just gotta be happy with cas 3 and cas to ras delay of 4 for decent clocks or performance.
UCCC isn't for Tight timings, it is like TCCD.. highier FSB speed..
If you want Tight get CE-5.

[Fission]

UCCC isn't for Tight timings, it is like TCCD.. highier FSB speed..
If you want Tight get CE-5.

Is that a "no?"

[politenessman]

thanx. the lower voltage helped . these are 0603 from newegg last week. no active cooling, but they get some overblow from the xp90. 2.59v vdimm and 284mhz 1/1 10x multi.

[Eldonko]

You can do CAS2 <200Mhz IIRC but I dont see why anyone would want to do that. :confused:

[Deathspawner]

You can do CAS2 <200Mhz IIRC but I dont see why anyone would want to do that. :confused:

Why do some people wear winter jackets in the summer? Because they are wierd :D

[bachus_anonym]

It really depends on the DIMMs, but usually 2.8v is as high as one should go when working with UCCC. Very often even 2.5v works great up to~270MHz, fully stable. So, it all comes down to experimenting and finding it on your own. More volts is needed to max it out once you start going tighter on latencies, like 5-3-3-3.0-1T.

As for CAS... I'm testing some UCCC DIMMs from Patriot now and those seem to work quite comfortably at that 245MHz 5-3-3-2.5 - SPi32M passes, but I have not tried SP2004 just yet. CAS2.0 does look too good, though. I honestly have not managed to even boot at DDR400...

[nn_step]

Is that a "no?"
it is a highly unlikely.. Possible but the odds are heavily stacked against you.

[k0nsl]

Couldn't even get CAS 2.5 to work at 250MHz with mine.

What refresh rate should 2GB HS have? I am running 133 MHz 1.95us right now.

-k0nsl

[Reinvented]

3684 or 100 1.95

Also - you probably won't see cas 2.5 or 2 till it's less than 248.

[elected]

What refresh rate should 2GB HS have? I am running 133 MHz 1.95us right now.

-k0nsl

A lot of people recommend 200mhz 15.6us (3120), 100mhz 1.95us (3684) and 166mhz 1.95us (4708) for UCCC so you are on the right path. I started with 3120 and gained stability at higher clocks with 4708.

[cirthix]

uccc doesnt like voltages too much, around 2.85 is good. cas2.5 is probably the best to run with overall.

they will do cas2, but at less than 200mhz, do not really worth doing.