Question re: adding RAM to my computer

I’ve googled myself to death on this, and haven’t found a clear recommendation, so I humbly submit for your perusal:

I currently have an AthlonXP 1800+ CPU on an MSI motherboard (KT3 Ultra 20-C/VIA KT333 chipset), 256 MB of PC2100 RAM. Currently, use it to access the web, and play games - mainly Unreal Tourney 2k4, but some other less graphic intense games.

Given that I currently get about 10 frames/sec in UT with moderate quality, I am looking for a performance boost, and plan on adding up to 512MB RAM (no more than that - $) and upgrading the CPU; I’ll also be upgrading from a GeForce MX440 to a Radeon 9700 Pro - yummy).

Since the mobo only supports CPUs with a 266 Front Side Bus, I have to add an AthlonXP 2400+ (Thoroughbred core, not the new Barton 333/400 FSB CPU) - got that figured out.

The mobo supports up to PC2700 RAM. If I keep my existing PC2100 RAM, I won’t bother to get PC2700 for hte new stuff, because the memory speed is dictated by the slowest RAM stick, and I won’t be buying a new PC for a while - by then PC2700 will be ancient. So I have two choices: increase my memory bandwidth from the current 2.1 GB/sec to 2.7, with only 512MB capacity; or staying at 2.1GB/sec, but increase total capacity to 768MB.

Finally to the question at hand: which is more of a performance boost for gaming - 512MB total at the faster 2.7GB/sec throughput, or 768 at the current throughput?

Compounding this issue, I’ve heard conflicting reports on other forums on a couple points - I’ve seen some say that once you’re above 512, performance boost form addt’l RAM is minimal unless you’re rendering 3D, or processing/editing video realtime (so why have 768 when 512 is all you’ll need); but some others say bollocks to that, 1 GB or above is where performance tops out (I tend to belive the latter, but IANA hardware expert). I’ve also seen some people say that the CPU Front Side Bus limits the memory throughput in those mobos (like mine) which support different maximum CPU (266) and RAM (333) FSB speeds; I haven’t seen anything refuting this last point, but not sure - although it’s curious why anyone would bother to support faster RAM when the CPU will just throttle it back. If this is indeed that case, then PC2700 would result in a negligible performance boost. I have also heard (but not confirmed) that filling all memory slots on your mobo (mine has 2) will drag throughput down.

Any ideas?

What operating system are you using?

The biggest boost you’ll receive with your current specs is from upgrading your GPU. Besides that, extra RAM can never hurt, as well as upgrading your CPU.

Unreal Tournament 2k4 is notorious for being a dog on all but the most elite gaming machines. You’re going to have to live with subpar framerates for a while, until you can upgrade most of your components.
NOTE: If you upgrade your GPU, make sure that you have proper ventilation. Too many times do people have poor perfermance from CPU or GPU overheating. Plus you don’t want to burn out your new graphics card do you?
You should see a tremendous increase in performance by just switching over to the Radeon 9700 Pro.

Basically, if you’re currently hitting the page/swap file them more memory will help - but if you’re not, it won’t.

The test I always use is to have the person using the machine fire up his/her “heavy side of normal” set of applications (IE, if you’re occasionally using a large Excel spreadsheet while you have a couple instances of your web browser open and a large DOC file open, fire them all up) and then switch between applications while doing some minor function in each that wouldn’t normally involve disk access (IE, edit the DOC file or recalculate the spreadsheet). If you see your hard disk light briefly (or maybe not so briefly) go crazy whenever you switch between applications, you’re probably hitting the swap file and could probably take advantage of more memory. Otherwise, otherwise.

You can’t increase memory bandwidth on your current system without buying a new motherboard AND CPU. As much as the chipset and memory manufacturers want you to believe it, you’re simply not going to be able to push more than 2.1GB/sec down an Athlon XP’s 266Mhz bus. That said, I’d suggest you buy DDR400 (PC3200) RAM for your upgrade, as it’s the only RAM manufactured these days, thus doesn’t cost any more than PC2100 or PC2700. It’s more future-proof, and since it doesn’t cost more, why not get it?

As for total amount of RAM, 256MB is fine for general usage in Windows XP. An upgrade to 512MB will strongly help gaming. Going beyond that isn’t really necessary, outside of specific applications. For example, I’ve been doing a lot of heavy disk I/O stuff recently, and the performance loss caused by XP constantly having to shuffle between RAM used as disk cache and RAM used by applications is getting tiresome. I’ll be upgrading to 1GB as soon as I can afford it.

Thanks for the replies. World Eater, I am running XP Home. **

Alien2022**, I’ve got three pretty beefy case fans, and the new GPU has a pretty slick heatsink/fan system that’s ported to exhaust the air away from the card, so ventilation shouldn’t be a problem, especially since I don’t overclock.

sevenwood, I don’t often have to access the swapfile, but I’m perilously close to doing so - right now, I just have MS IE open, and I only have about 60 MB of 256 available. So I figure it couldn’t hurt to slap in a few more MB, and Meg for Meg, 512 is a better deal now than 256 is.

Alereon what you say makes perfect sense, that a board with a 266 Mhz CPU bus won’t fully utilize a 333 Mhz RAM bus, and I’ll run with that. But the irrational, naive part of me thinks “Why would the mobo mfgr make a board that can’t fully utilize it’s RAM pipe? Wouldn’t that be disingenuous?” Stupid me. Honestly, the DDR400/PC3200 isn’t a choice. It’s only a few bucks more, but I don’t know if my mobo will support it, and it’ll be so long before I get my next system that DDR550 will probably be at a reasonable cost.

Thanks for the feedback; I’m thinking at this point that I’ll add 512 to the 256 I already have. I thought about replacing the motherboard altogether, going with top-notch processor, RAM, etc., but I can’t really justify the cost considering what I use the system for. And I really don’t want to reinstall everything all over again.

Thanks again.

By the way, I’ve gotta say that after visitng about 50 or so hardware forums on the internet (only a very few of which impressed me enough to lead me to post my query), and finally thinking to post here, this is the place where I saw the most relevant answers, in just a few posts. And, unlike several other forums, no one here said the following: “heres what u do - uninst ms and get linux, cuz bill gates iz evil open source roolz blahblahblah”

This is why the SDMB rocks.