2GB vs 3GB

[s_s_tucker]

I currently have 2 X 512MB PC5400 DIMMS (not overclocked). Time to add more RAM and I am wondering if adding 2GB would really make a bigger difference than adding 1GB? I can get additional 1GB for $14 so this is a pretty cheap upgrade-2GB is about $40. Right now I am playing Oblivion and it is running decent with some latency (I have a 384MB nvidia 8800 graphics card)-running XP. So 2GB or 3GB??-which is better performance for the price?

 

[jonpaul37]

best bet is to go with 2 X 1GB of PC6400, it can be gotten really cheap on newegg, and take out the 2 X 512MB RAM as a whole and do not use it with the new 2 X 1GB of PC6400 RAM.

The reason i say this is because you're going to be using the new ram in dual-channel mode as you are right now with the 2 X 512 kit you have, but if you combine them, it'll still be in dual channel mode, but the 2 X 1GB kit will auto-slowdown to the PC5400 kit specs and essentially will underperform.

In this case, just get a 2 X 1GB kit of PC6400 DDR2 800 kit and use only that...

 

[aevm]

Go for 3 GB if you can. RAM is usually the most cost-effective upgrade, and these days RAM is dirt-cheap too. My feeling is that jumping from 1GB to 2GB will make a huge difference, and jumping from 2 GB to 3GB will make a smaller difference but still important.

Here's an article that shows the difference between 2GB and 4GB. I don't have one for 2GB to 3GB, but you get the idea.
http://www.bit-tech.net/hardware/2008/07/08/is-more-memory-better/5

 

[jonpaul37]

if you get 3GB you will lose Dual-Channel mode, put it this way... you have 4 RAM slots, 2 are green (or whatever color) and 2 are red (or whatever color) if you buy 2 X 1GB and put them both in the green slots, you'll be running that RAM in dual-channel mode, the moment you put another 1GB stick of RAM in one of the red slots, you lose Dual-channel mode and you'll lose a little performance of the RAM. In my opinion, it's better to have 2 X 1GB running Dual-Channel with Win XP, not 3 X 1GB

 

[ausch30]

You could just get a set of DDR2 800 2x2gb which can be found for $30-$40 and although you won't have access to all 4gb, it would be your best performance option. Something like this for $25 after MIR with free shipping or this for $38 after MIR with free shipping, and if you decide to move up to a 64bit OS in the future you'll have access to it all.

 

[ausch30]

if you get 3GB you will lose Dual-Channel mode, put it this way... you have 4 RAM slots, 2 are green (or whatever color) and 2 are red (or whatever color) if you buy 2 X 1GB and put them both in the green slots, you'll be running that RAM in dual-channel mode, the moment you put another 1GB stick of RAM in one of the red slots, you lose Dual-channel mode and you'll lose a little performance of the RAM. In my opinion, it's better to have 2 X 1GB running Dual-Channel with Win XP, not 3 X 1GB

He stated in his OP that he has 2x512 not 1x1gb

 

[jonpaul37]

He stated in his OP that he has 2x512 not 1x1gb

That is correct, but in my first reply, i stated that if he still used the 2 X 512, any other memory he used (like the 2 X 1GB PC6400) would default to the specs of the 2 X 512MB kit, thus lowering the performance of the 2 X 1GB memory, this is why it's better to just stick with the 2 X 1GB memory...

 

[geofelt]

You can put 1.5gb on each channel and operate in two channel mode.
But, You can't go wrong with a corsair 2x2gb kit for $25 afrer rebate:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820145184

 

[4745454b]

Another vote for 2x2GBs. This is the route that I picked. Yes for 32bit windows I won't see the full 4GBs, but at these prices your almost crazy to not simply get the 4GB kits. $40 or less for 4GBs of ram is great, you won't have to ever worry about upgrading your ram again. With DDR3 gaining, the price of DDR2 can only go up.

 

[Onus]

I like the second set of 2x2GB that ausch linked. It will run at the JEDEC standard 1.8V, for no-muss no-fuss installation. It can also be overclocked well above DDR2-800. I had mine up to DDR2-960 purely by accident, and without a voltage increase. As it was by accident (I'd forgotten to set a ratio), I didn't do formal testing, but it was that way for weeks through everything I do (mostly Guild Wars and a lot of general stuff), and I never had a crash.

 

[s_s_tucker]

Thanks for all of the comments-great info. A couple of things I didn't put in the original post: I have 2 open slots so will definitely get a 2X kit. Also specs on moboard only support 667Mhz---so will it do any good to put in anything higher? Like DDR2 6400??? Would I be better to replace 667MHz and go with 6400??? Thanks

 

[evongugg]

Still get DDR2-800. You should be able to overclock anyway past 667MHZ.
The price difference is very small.
You will also have tigher timings available.

 

[geofelt]

Thanks for all of the comments-great info. A couple of things I didn't put in the original post: I have 2 open slots so will definitely get a 2X kit. Also specs on moboard only support 667Mhz---so will it do any good to put in anything higher? Like DDR2 6400??? Would I be better to replace 667MHz and go with 6400??? Thanks

Ram can operate slower than spec, but not higher. DDR-800 is usually cheaper, which is why the Corsair kit is a no brainer. In truth, the C2D processors are not sensitive to ram speeds, the quantity makes much more of a difference. Only overclockers should care a bit.

 

[ausch30]

The Corsair set I linked and geofelt mentioned runs at DDR2 800 1.9v which is .1v over the JEDEC specifications for DDR2 which means that it's likely DDR2 667 that Corsair guarantees to run overclocked to those specs.

As jtt283 correctly mentioned the Mushkin I linked is specified to run at 1.8v which is the JEDEC standard for DDR2 but it is very likely that both sets have settings for 667 and 800 programmed onto the SPD (Serial Presence Detect) chip.

This is from my current RAM

It was sold as DDR2 1066 but as you can see there are several different settings programmed in. The JEDEC settings are "official" settings and the EPP (Enhanced Performance Profiles) settings are overclocked settings the manufacturer guarantees will work.