Corsair Dominator DDR2 1066MHz questions

[alert101]

Hi,

I have two kits of 2x1GB Corsair TWIN2X2048-8500C5D = 4x1GB memory modules (http://www.corsairmemory.com/_datasheets/TWIN2X2048-8500C5D.pdf).

mobo: Asus P5K-E WIFI/AP-edition
proc: C2D E6750 (G0)

Now I'm running the proc at stock speed 8x333 (2.66GHz) and the memory at 500MHz (1GHz) with FSB : DRAM ratio at 2:3, timings 5-5-5-15-2T . Earlier when I was running only 2x1GB I could run the memory at 1066 MHz, but when using four modules I start getting errors when I go above 1020 MHZ.

Question 1: Is DDR2 always limited to a command rate of 2T? On my previous system (AMD / DDR400MHz) the system was limited to 2T when using 4 memory modules (integrated memory controller issue), but with 2 modules you could run 1T.

Question 2: Anyone have a similar setup and what kind of OC settings?

Question 3: What kind of timings have you achieved with the TWIN2X2048-8500C5D?

Question 4: If I would OC, would the following make sense, or should I try something else?
■Proc @ 400x (7 or 8) = 2.8GHz or 3.2GHz
■Memory @ 800MHz 4-4-4-12 (if possible) FSB : DRAM ratio = 1:1, correct?

Please, I'm not interested in anything regarding other brands of memory or when using a Quadcore or whatever. The system above is the one I ALREADY have at home = I already have the parts. So comments like "You should buy this and that instead" are irrelevant. Thank you. 😉

 

[Scotteq]

Electrically, 4 DIMMS are harder for your mobo to drive than 2. You can increase Vdimm a bit, and maybe also bump your FSB a notch. That's often enough. But some mobos weren't really designed to drive 4 sticks of high performance RAM. Until very recently, 2 was considered to be *plenty*, so testing/certification was done with that in mind.


At stock speeds, my board will drive the same memory to 1066, but when I overclock I get errors like you have, and at about the same point. DDR2 1000 on 4 sticks while overclocking?? Yup! But it did not like going any higher than that. I played with a number of setups, but in the end, I cranked my FSB to 400Mhz, set the CPU Multi to 8, set the RAM to DDR2 800 (1:1), and declared victory.

YMMV, of course.

 

[tmike]

What kind of timings have you achieved with the TWIN2X2048-8500C5D

my TWIN2X2048-8500C5D will not do one iota better than Corsair said it would (1066 5-5-5-15 @2.1v), no matter what i tweak. i guess my pair were the runts of the bin.

 

[nel]

What kind of timings have you achieved with the TWIN2X2048-8500C5D

my TWIN2X2048-8500C5D will not do one iota better than Corsair said it would (1066 5-5-5-15 @2.1v), no matter what i tweak. i guess my pair were the runts of the bin.

Well, U can try tweaking ur neck

 

[nel]

actually, the Asus P5K-E WIFI/AP-edition just came out last year (WHEN MOST PEOPLE USED 4GIG NOT LIKE 10 YRS. AGO) so this board definitely can handle 4 gig of 1066... Did u try updating ur bios... try getting the one that say enhance ram compatibility maybe then will recognice ur ram

 

[hughyhunter]

This is a HUGE leap in technology the tech computer industry has yet to accomplish. First and formost 4 sticks of RAM are not stable in any overclock known to mankind.

Can you even pass super pi at stock settings? The reason why I ask is because I am not passing super pi at stock settings and i'm running stock speeds.

Also you cant run 2T command rate in any rig with 4 sticks. Just cant do it!

I bet you that if you take two of those sticks out right now you will get a very stable overclock to 1066 and you will not even notice a performance hit. There really is not much that will utilize 4 Gigs right now anyway. GAmes wont make much of a difference... and if they do it will work better with a 2x2 setup not a 4x1.

I'm curious to know how it turns out. I dont think it's a matter of tweaking anything or bad parts... You just cant run 4 sticks stably in any mobo yet... I have a friend that swears by it... and he has a bachelors degree in electrical engineering! Well that doesnt mean much but he's pretty smart!

 

[hughyhunter]

It sounds to me though that the person does not want to get any other memory... he wants to work with what he has and try to achieve 1066 with 4 sticks.

Well if you do decide to work with what you have than you have either one of two options IMO. You can take two sticks out and overclock to 1066 or you can leave four sticks in and be happy with something like 950-1000.

 

[nel]

1066 DRAM is not an overclock for that motherboard, however;
and, it's a stock speed for PC2-8500 / 8 = ~1066.

See the Table above, e.g.:

FSB / DDR2
1333 / 1066*
1066 / 1066*

* If you install a DDR2-1066 memory module,
make sure that you set the DRAM Frequency item
in BIOS to [DDR2-1066MHz]. See section 4.4.1
Jumperfree Configuration for details.


1066mhz its an overclocked version of 800mhz,,, why would say 1066mhz is a default speed????

 

[Scotteq]

Paul - I have 4 Dimms of the same memory on a different Bios/Board. The Default/Auto settings are DDR2-800. There is an EPP (Enhanced Performance Profile) for DDR2-1066 (5-5-5-15 @ 2.1v) programmed into the SPD, and that does display on CPU-Z. But you have to go into the Bios and set it manually. The computer will default to 800.

***

With 2 DIMMS, 1066 was perfectly straightforward. Go into the Bios, change the settings to what Corsair says, and restart. Done Deal, and stable as long as I want it to be. While playing with overclocks, I got to DDR2 1200 at 5-5-5-20, 2.3v with the single pair on the same setup. 8 hour P95. But I wanted to run 4. And so I do.

Regarding my experience working with 4 of these at once: As I mentioned before, I was able to get to DDR2 1000 at 5-5-5-15 at 2.2v. I could go a little higher than that and still post and get to the OS, but it wasn't stable. At 1K it was 8 hour stable on P95, and passed the torture test in Everest Ultimate. I can't claim 'bulletproof' stable because I didn't leave P95 running for the full 24h, but that is certainly a working overclock. Booted to the OS, I was able to Game, etc... Ran kinda warm, though. Not horribly so. But I had that in the back of my head as one of those niggling details that eats away at you until you handle it. This was the reason I put the 4 DIMMS back to 1:1 (DDR2 800).

Quite frankly, given the same CPU overclock, I didn't see any difference in day to day operation between DDR2-1000 and DDR2-800. It benches a little bit slower on memory in Everest, else was the same. Except now the DIMMS loaf along at 1.9v and remain cool to the touch with no additional fan. Every once in a while I think about tightening the timings up some more, since the individual modules are certainly capable of running a lot faster than they are now. But then I think I'd like a sandwich, too, or maybe come cake - Cake is good. <wanders off to the kitchen>

I'm quite happy with this setup, actually. Fast, stable, and cool running. 😍

Oh: DFI Lanparty P35 T2R mobo, Sept 13th Bios, OCZ 900W PSU fed in turn by an APC UPS...

 

[hughyhunter]

Every once in a while I think about tightening the timings up some more, since the individual modules are certainly capable of running a lot faster than they are now. But then I think I'd like a sandwich, too, or maybe come cake - Cake is good. <wanders off to the kitchen>

I'm quite happy with this setup, actually. Fast, stable, and cool running. 😍

Oh: DFI Lanparty P35 T2R mobo, Sept 13th Bios, OCZ 900W PSU fed in turn by an APC UPS...

I think your funny

 

[alert101]

Thank you for your comments and answers regarding my questions.

First of all... I didn't ask for advice on how to get the memory running at full stock speed (1066). I really don't care about those last few MHz, 1000 vs 1066. In real life performance that shouldn't matter...much. 😀

I think I'll try the same setup as Scotteq:
" ...but in the end,
I cranked my FSB to 400Mhz,
set the CPU Multi to 8,
set the RAM to DDR2 800 (1:1),
and declared victory."

@Scotteq: If you still follow this thread... What kind of timings have you used with those settings? Stock 5-5-5-15 or have you tried tightening them a little, like 4-4-4-15 or 4-4-4-12 or something in between?

@Supremelaw: That's something that I've completely forgot to check...the QVL! Never thought that adding two sticks of the same memory that already performed fine could cause problems (bought the additional 2x1GB later on). Never mind that. 4 sticks seems to run just fine, not quite at the rated stock speed though.

 

[Scotteq]

Heya Alert - Up until this last weekend, I was happy with the rated 5-5-5-15. So, 6 months. But... You know how I mentioned earlier having that little bug in your ear?? The one that won't go away until you scratch it??

Well...


They're at 4-4-4-12/2v now. <grins> I'd post a couple screenies, but that'll have to wait until tonight when I get home. So yah - There seems to be room to tighten up the timings when they're downclocked a bit.

 

[alert101]

It's a nasty little bug that one... 😀

Good to know that I should be able to tighten the timings. Have to take a look at them someday and then run Memtest for a couple of hours. Thanks for the info.

 

[hughyhunter]

First of all... I didn't ask for advice on how to get the memory running at full stock speed (1066). I really don't care about those last few MHz, 1000 vs 1066. In real life performance that shouldn't matter...much. 😀

Didnt know that you didnt really want to run your memory at stock (1066) speeds. Why would you buy high performance memory if this wasnt your goal?

Question 1: Is DDR2 always limited to a command rate of 2T? On my previous system (AMD / DDR400MHz) the system was limited to 2T when using 4 memory modules (integrated memory controller issue), but with 2 modules you could run 1T.

Question 2: Anyone have a similar setup and what kind of OC settings?

Question 3: What kind of timings have you achieved with the TWIN2X2048-8500C5D?

Question 4: If I would OC, would the following make sense, or should I try something else?
■Proc @ 400x (7 or 8) = 2.8GHz or 3.2GHz
■Memory @ 800MHz 4-4-4-12 (if possible) FSB : DRAM ratio = 1:1, correct?

So back to your original questions. 1. No you cant run 2T timings with 4 sticks (but you already knew that.... we told you already) 2. I personnally built my friend from work a system with the same memory just different mobo and proc. The mobo was a Foxconn X38 with a Q6600 G0 stepping. Although he was only running two sticks of that memory the performance is relatively the same. 3. If you buy high performance memory there is a reason the manufacturer ships them with those "specific" timings. A important thing to remember is that timings and command rate arent everything. If you run the stock timings and the frequency at stock you will get a much more stable overclock than to reduce (tighten, make faster) your timings and run a slower frequency. And it should perform better considering it's running at what the manufacturer intended. This is why Corsair does EPP... To get stable overclocks at stock speeds! 4. I would if I were you try to run a 250 FSB at a 1:2 ratio and set your multi at something like 12 (of course if you multi can go this high... I wouldnt know because I dont have that chip or have I installed that chip on any mobo).

 

[Scotteq]

Alert - Here's those screenies:

 

[Scotteq]

Stressed it in Everest over last night to check voltage/temp differences:

 

[evongugg]

Youcan test different timings. Not all modules are the same. Just make sure you run Prime95 to make sure there are no errors.

 

[kentuckyranger]

This is a HUGE leap in technology the tech computer industry has yet to accomplish. First and formost 4 sticks of RAM are not stable in any overclock known to mankind.

Can you even pass super pi at stock settings? The reason why I ask is because I am not passing super pi at stock settings and i'm running stock speeds.
My Rig passed it running 36 Hours.

Also you cant run 2T command rate in any rig with 4 sticks. Just cant do it!
My Rig runs at 2T, it won't run at 1T.

I bet you that if you take two of those sticks out right now you will get a very stable overclock to 1066 and you will not even notice a performance hit. There really is not much that will utilize 4 Gigs right now anyway. GAmes wont make much of a difference... and if they do it will work better with a 2x2 setup not a 4x1.
Now I have heard of this but my Rig runs fine so I haven't tried it.

I'm curious to know how it turns out. I dont think it's a matter of tweaking anything or bad parts... You just cant run 4 sticks stably in any mobo yet... I have a friend that swears by it... and he has a bachelors degree in electrical engineering! Well that doesnt mean much but he's pretty smart!
Right now with my 4GIG of Dominator RAM I'm running rock solid and stable with 5,5,5,15 2T 2.15V

I think it just has to do with the way manufacturers set up their M/Boards and what Chipsets they use.
Allot say that the nVidia Chipset in my M/Board sucks but since this Rig has been running I've had nothing but smooth sailing out of it. I did have some issues with nTune but after deleting it things came back to normal.
You just can't tweek the BIOS from Windows and expect things to go right.
Manufacturers are trying to make O/C too simple and it's just not working.
Dang, I got on a rant again, Time for my Meds, LOL!
Anyway, RAM is one of those things that can really give the Overclocker allot of Headaches it He/She lets it.

 

[hughyhunter]

Man I'm stupid... I meant to say you cant fun 1T timings with 4 sticks. This is one thing that I think really sucks. I dont really know what the real world difference is though.

My rig is running 4 sticks under spec right now... even though the memory is cheap and I just cant get it to pass super pi.

 

[hughyhunter]

Kentuckyranger: I was looking at your configuration. I noticed you have an exteme proc with 2 ultras. Dont you think your score is a bit low on 3Dmark06 for what you have? The only reason I ask is because I was reading on a different post a guy getting a solid 17k with a Q6600 and two 8800GTs. His was o'cd to 3.5 but still think you should be smoking that score by a few thousand.