3 + 6gb, how foolish?

JonJ678

JonJ678

JonJ678

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Hey guys. I'd like to get the 6gb 1600mhz corsair dominator. However I don't think I can fund it at present, so an considering getting the 3gb kit then adding another 6gb a few months down the line. Ignoring the standard 'you don't need much ram' objections, what effect would this have on overclocking an i7?

I'm guessing not good, but it might be negligible. Any ideas welcome, i7 cooled with an ek supreme.
 
4 or 8... interesting job getting that working in tripple channel...

3 is 3x1GB, and 6 is 3x2GB.

4, 8 arnt divisible by 3.

Anyway no problem at all having 3GB + 6GB kits.

Each channel will get a 1GB, and a 2GB stick, just make sure you put the ram into the channels evenly.

IE
Chan 1 slot 0 1GB, Chan 1 slot 1 2GB
Chan 2 slot 0 1GB, Chan 2 slot 1 2GB
Chan 3 slot 0 1GB, Chan 3 slot 3 2GB
etc.

What you would want to avoid would be
Chan 1 slot 0 2GB, Chan 1 slot 1 1GB
Chan 2 slot 0 1GB, Chan 2 slot 1 2GB

The slots on the board should be well marks, and are normally colour coded to avoid such errors anyway :). As long as the ram is good quality it shouldnt affect performance in a bad way, at worst you may need to slacken the timings a tiny bit, but only if you start getting errors.

I have 6GB on my Q6700 system, which is a pair of 1GB modules, and a pair of 2GB modules, and I didnt even need to up the voltage or slacken the timings, it all works perfectly... At the end of the day its just a matter of the quality of the individual ram chips.
 
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This is better news than I was expecting, thank you. I'd have probably arranged the ram like that automatically, but not sure I'd have thought of it. Cheers

On a similar note, but hopefully I won't need to start a new thread. What speed ram? I'm struggling to get an answer out of google for it, it seems 1600mhz / pc-12800 is fine for 4ghz. I can't find out why or if it can do over 4ghz without being itself overclocked.

I think the lowest divider on the UD5 is x6. 200blck x20 is 4ghz for a 920, so is the ram speed required 6x200=1200mhz or something else? I think the blck limit on the UD5 tends to be around 220, which would be 4.4ghz. So is 1600mhz ram fine for this too?

I'm not worried about bandwidth between ram and processor, it's raw processor speed I'm interested in. So timings just don't matter. I'd kind of like to be able to get slower ram than 1600mhz if possible, but want the board and processor to be the limiting factor and not the memory. I hope someone clears this up for me :)
 
Running 6 1G sticks will probably limit your maximum overclock compared to 3 2G sticks. The memory controller is in the uncore part of the i7 CPU, which has a fairly tight TDP.
 
But how about three 2gb and three 1gb sticks compared to six 1gb or six 2gb sticks?

What do you mean by TDP? I think overclock will be limited by the memory controller, any idea how this varies with temperature?
 
TDP = Thermal design power

I believe that the problem is getting six sticks of RAM running while overclocking the CPU, whether those sticks are 512M 1G or 2G.
IIRK running 6 sticks uses more power on the memory controller than 3 (Although I don't think the sticks are actually powered directly by the memory controller, but the memory BUS is).
 
TDP applies to the processor as a whole does it not?

Otherwise that sounds about right. It'll be using 6 sticks eventually anyway, so this is a problem I'll have to accept. Hopefully I'll solve it with water, otherwise my worries about ram speed may prove irrelevant. 6gb isn't enough, 9gb is at a push. I fear I'm just going to have to wait until I've saved enough to buy 6gb outright.

Any thoughts on the question of which speed Hazard?
 
The i7 has 2 TDPs IIRK one for the uncore and one for the actual cpu cores.

As for speed of memory, I don't think it's worth getting anything faster than 1600 CAS8, and even that's overkill, but at least these kits are cheap.
 
Ah, fair enough on the TDP.

That's the conclusion I'm reaching, but what blck does 1600mhz cover you up to before you have to overclock the ram?

1600 CAS 8 is what I'm looking at presently, but minimum required speed seems to be more complicated than fsb *2 from socket 775
 
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