Does having 4GB limit overclocking?

nlel1975 · 28 May 2007 at 19:08

I`m sure I read a thread on here where someone couldn't get above 2.88mhz whilst using 4GB but could get 3.2ghz when just using 2gb.

So my question is does having 4GB (4x 1GB) affect overclocking? I`m talking about on a 965P DS3 board becuase I`m thinking about getting 4GB as its so cheap atm and games will use it in the next 1-2 years.

WJA96 · 28 May 2007 at 19:20

There is always the risk that a mismatch in the RAM pairs could cause instability. This is lessened if you buy two pairs at the same time rather than two pairs some time apart.

simonnance · 28 May 2007 at 19:28

running my 4x1GB 10th Annis at 525Mhz 4-4-3-9-2T

At looser timings (5-5-5-15) i can get them up to 575Mhz.... but i actually get better ram bandwidth with lower freqs and tighter timings. Still trying to tighten up the sub-timings, think thats about as low as the main ones will go.

So no.... no real disadvantage in OCing

WJA96 · 28 May 2007 at 19:58

simonnance said:
running my 4x1GB 10th Annis

well, as these were specially speed-binned from 1 weeks production I'm not necessarily certain these are a good example.

simonnance · 28 May 2007 at 20:22

however my overclock is pretty similar to my old 2x1GB one, so any drop is probably the result of having to use the settings that are stable on the worst performing DIMMs, rather than an innate disadvantage using 4x1GB in overclocking.

That my DIMMs will overclock better or worse than the OPs is no matter.... all i am saying is that going to 4 sticks will be unlikely to have a negative effect on HIS overclock.... not boasting about mine being better or worse than his.

james32 · 28 May 2007 at 20:29

WJA96 said:
There is always the risk that a mismatch in the RAM pairs could cause instability. This is lessened if you buy two pairs at the same time rather than two pairs some time apart.

ditto but buy 4 sticks together saves even more hassle

as i bought another 2gb of cellshock other day and they would't
run side by side with the older cellshock ( difrent bios settings)
the new cellshock are epp, now iam going have flash them to
get the 4 of them to work together.

WJA96 · 28 May 2007 at 20:30

simonnance said:
however my overclock is pretty similar to my old 2x1GB one, so any drop is probably the result of having to use the settings that are stable on the worst performing DIMMs, rather than an innate disadvantage using 4x1GB in overclocking.

That my DIMMs will overclock better or worse than the OPs is no matter.... all i am saying is that going to 4 sticks will be unlikely to have a negative effect on HIS overclock.... not boasting about mine being better or worse than his.

I disagree - your DIMMS are very closely matched - the overclocking potential has nothing to do with it. Would you expect 2 Rev1.0 Corsair XMS2 RAM sticks to work well together with two Rev2.0 Corsair XMS2 RAM sticks? You might, but it's a terrible combination. The Rev2.0's with their Elpida chips don't clock at all well, whereas the Micron-equipped Rev1.0's love to clock. In that case you might get 500MHz FSB with the Rev1.0's but add in the Rev2.0's and your overclock could be limited to 430FSB.

My whole point is the closer together you buy the RAM, the more chance you have of it working together irrespective of the ultimate headroom available. The Anniversaries were selected to a very tight specification and are extremely well matched, so they make an excellent choice for a 4-stick overclock, but not a good example of someone who had 2 sticks and added another two?

WJA96 · 28 May 2007 at 20:33

james32 said:
ditto but buy 4 sticks together saves even more hassle

Agreed - in an ideal world the RAM manufacturers would supply 4 x 1Gb kits with 4 sticks tested together like they do in the paired kits.

nlel1975 · 28 May 2007 at 20:36

Well I`ve just added another 2x 1GB Crucial PC5300 CAS5 Kit to the same order which had already had 2x 1GB Crucial PC5300 CAS5 Kit. So now I have 4x 1GB for £ 73.10 ex VAT

They should be well matched and I figure to get them while the price is pretty much bottoming out. It gives me a reason to try out Vista 64 bit too.

jbloggs · 28 May 2007 at 20:39

Just bougt another 2GB Crucial Ballistix PC6400 kit, so hopefully I won't run into any problems.....

nicktay2605 · 28 May 2007 at 20:43

I've got 4Gb and get good overclocking, but then like WJA suggests, I bought mine pretty close together so they matched well.

trojan698 · 28 May 2007 at 21:08

IMO it'll be limited insofar as your overclock can only be as high as your worst stick of RAM. So with, compared to 2 sticks, you will be more likely to hit a wall at a lower overclock with 4 sticks of RAM. Hope that makes sense, it does in my head.

simonnance · 28 May 2007 at 21:13

WJA96 said:
The Rev2.0's with their Elpida chips don't clock at all well, whereas the Micron-equipped Rev1.0's love to clock. In that case you might get 500MHz FSB with the Rev1.0's but add in the Rev2.0's and your overclock could be limited to 430FSB.

Which is exactly what i was trying to say, your overclock will be limited by the weakest set of chips, not by the fact that you are running 1x4GB.

If you plan to overclock, then getting matched sets is the most sensible option as the overclocking variance will be lower. mixing different Rev sets will obviously limit your highest overclock.

The only real limitation is being forced to use 2T.

bfar · 29 May 2007 at 12:37

Yes. 4 sticks of RAM makes the Northbridge work a lot harder because it obviously has a lot more work to do.

The Northbridge is already overclocked when you increase your frontside bus, and it's under even more stress when running 4 sticks of RAM.

Therefore, yes, 4 sticks of RAM can hinder your Overclock if the Northbridge craps out.

Cuchulain · 29 May 2007 at 12:41

bfar said:
Yes. 4 sticks of RAM makes the Northbridge work a lot harder because it obviously has a lot more work to do.

The Northbridge is already overclocked when you increase your frontside bus, and it's under even more stress when running 4 sticks of RAM.

Therefore, yes, 4 sticks of RAM can hinder your Overclock if the Northbridge craps out.

Don't most modern boards lock the NB frequency?

Yellowbeard · 29 May 2007 at 19:59

"IF" your memory can hit a certain speed, the NB is going to be the most critical element in a 4 x 1gb OC. In this case, I would fully expect a P5K to OC better with 4 DIMMs than a 965 based board.

In virtually every case I have ever seen where users tested 4 identical DIMMs for max OC vs 2 of those same DIMMs, you lose approximately 50mhz of OC due to the load on the NB.

If you try 4 DIMMs, make sure your NB is well cooled as you will likely need to add a bit of NBv for stability while OCing.

pieman109 · 30 May 2007 at 02:13

I found that going to 4gb DID affect my overclock (thats on the DS3 in me sig). with 2gb of geil I could get the memory speed up to 925mhz-935mhz without any probs at 5-5-5-16, but with a further two sticks, I can't get above 805mhz no matter what I try, more volts, slacker timings, etc.
One question though, is it easier to get and decent overclock with 2 x 2gb memory than with 4 x 1gb memory?

Yellowbeard · 30 May 2007 at 02:19

pieman109 said:
One question though, is it easier to get and decent overclock with 2 x 2gb memory than with 4 x 1gb memory?

Technically yes......when the kits are available. The higher speed DDR2 2gb DIMMs are still VERY hard to produce. Those that are currently available are in VERY short supply. But, even though the ICs are more dense, 2 x 2gb is significantly less chipset load than 4 x 1gb.