More Ram---MAYBE.
" Better performance" is very subjective.
And on late-model,higher end PC's there's a lot of possibilities and consideration.
RAM:
Your machine is likely Dual-Channel RAM capable.
IF>you have a single 1gb stick,,,
a Matching 1gb stick can enable Dual-Channel Mode.
That's a actual SPEED BOOST in the Function,,,In addition to benefits of added Capacity
IF>You already have D-C enabled,,,then You've got 2 x 512mb Ram---already a Matched Pair.
To simply ADD "1gb",,,one of the existing sticks has gotta go.
And so will the SPEEDY DualChannel function with it.
And you'll then only have 1.5Gb--In Effect adding SLOWER .5Gb for the Full Price of a 1gb stick
(Cuz ya "threw away" 1 existing 512mb piece,,right?)
IF>>You have 3 Ram Slots,addin a 3rd stick Disables DualChannel
MAYBE..have to buy 2 1gb sticks to get 2Gb Total in Dual Channel Mode.
GENERALLY--- 1Gb is not a handicap,,it's sufficient.
To get an actual Gain in Perf depends on existing config.
You Could spend a bunch of $$$ and not really get much useful gain.
VIDEO Cards....
Up till recently,,MORE RAM was KING of Upgrades--biggest bang for Buck.
Lately,,,
-OS's Manage RAM Better,,
-Modern CPU's & Chipsets Manage RAM better
-RAM is Faster & more efficient
-Most Machines come with at least minimally "sufficient" amount of RAM (Older machines typically had HALF or Way Less of what would be "minimally sufficient" 32 &64Mb vs 256mb for example)
So RAM these days,,in certain respects,,is No Longer necessarly "King"....especially in terms of "bang for buck"
VIDEO CARDS have become extraordinarly Advanced,,,and Expensive.
RAM got Cheaper,,TONS cheaper.
PC Builders tend to use Much more Generous RAM,,,while "shorting us " on Vid Card Specs.
So often times,,$$$ Spent on Graphics Upgrades will yield More Improvement than extra RAM.
It's a matter of COMMERCE,,,not so much Technology.
Mfgrs gotta cut corners to be Competitive.
More RAM is lots cheaper than Graphics for Builders.
Upgraded Vid Cards can also reduce load on both CPU and RAM,,in addition to their own intrinsic contribution to performance.
So,,,Graphics Upgrade "can" Improve Performance in THREE areas.
Very POSSIBLE to get a better Gain/Value via a VidCard upgrade.
SOUND:
Add-On Sound Cards remain popular,,even though lots of folks are satisfied with "Built-In Sound".
Beyond Improved Audio,,many sound cards reduce load on CPU and add to PC's overall perfomance.
MOST ALL PC's these days have enough CPU power,,that even though the Gain is REAL,,,it's minimal,,and probably not Noticeable
.Hard Drives....
There's some AWESOME fast HDD's available these days.
REAL-WORLD gains for "average users/Apps"????
Windows will load in 20~30 seconds from cold-boot,vs 30~40 seconds.
Is a 10 second reduction in Boot Times worth a couple $100??
Not worth MY $200.
For SOME Users,,and SOME Apps,,Ultra Perfomance HDD's are just the ticket----but,somewhat a waste of $$$ & effort for many folks
CPU.....
Frankly,,I do NOT know any of the AMD 64's very well.
But from the little that I think I know,,a 3500+ is very near the "max" in terms of speed.
A 200Mhz gain from a direct replacemnet Upgrade to "Max" is simply NOT worth the $$$
The NEWEST AMD's,,DualCore ones,,,would give a big boost.
No Doubt,,they'd be NICE for anyone doing anything.
But,,,would it be USEFUL,,,and worth the $$$.???
All depends on the uses it's put to,,,and the expectations of the User.
SOME ..."FREE"Horsepower can possibly be gained via Moderate Overclocking.
Most Bios SetUp settings allow raising the FSB settings"Front Side Bus".
(It's far more complicated than this,,,lottsa variables--but GENERALLY>>>)
Increasing Bus Speed raises Speeds on EVERYTHING,,CPU,RAM,Graphics.
A 3500+ Overclocked from 2.2ghz to 2.4ghz a 200ghz gain,,
will outperform
A 3800+ at Standard Settings running at SAME 2.4ghz
Same CPU Speeds in "Both Computers"
But the OC'd one has it's CPU running at Faster Bus Speed,,along with it's Ram,Graphics,HDD,Sound.
=== Faster Computer Performance Overall
Some "FREE POWER" tweaks
*Raise FSB in system Bios to maximum stable settings(usually 10% or less,,but ya never know How Much till you Try)
Most wont do more than +10%,,but 5~7~10% is a decent boost,,forFREE
*LOWER VidCard resolution And Color Quality
Many folks do not like the "look" of Low Res's.
Even so,,600x 800 Res w/ 16bit Color gives a substantial boost in frame rates.
*Vid Card Drivers...there's a variety of "custom" or advanced Drivers which allow OverClocking VidCard.
Omega Drivers are oem drivers which have been optimized & added-features.
If they support a particular PC/OS/VidCard setup,,it can be "free power"
...........................................................................
BEFORE spending $$$
I'd suggest getting an idea where YOUR Pc's weakest/strongest points are.
PCPITSTOP.com has a variety of tests.
their "FULL TEST" will tell You many specific details about YOUR PC,,,and also allows a Comparison of Yours vs their Test Database aka "everybody Else's PC who've tested there".
It's usefull for a guestimate comparrison to see how YOUR various hardware rates vs Other similar PC's.
If You're Average or Above in any area,,you know to look for Other areas to consider improving.
If You're substantially BELOW averages,,then That's a Bottleneck in your comparative performance and worth investigating Improvement possibilities.
http://pcpitstop.com/
Click FULL TEST on l/h menu
It loads a small program,,NO Spyware-Never,Ever,and it's Free.
No need to create account,unless you wanna archive your results THERE.
Takes a couple minutes.
On Results Screen:
"SYSTEM" > "External Clock Speed " is FSB speed/FrontSideBus
"Memory" >>will indicate how many RAM slots you HAVE,& are in use
"Video Board">>You can Test Changes in Resolution by chaning the settings,then re-running the test,,,noting differences in graphics speed.
It's all sorta "Lite weight" analysis as far as such things go,,but it's pretty good for getting a qick & easy Idea of your PC's strong/weak points,,,compared to similar PC's
.....................................
Anyway,,,MORE>Bigger>Better is never a Bad thing.
But those last few percentages toward achieving BEST/Maximum invariably come at Diminishing Returns in VALUE/Cost Effectiveness.
And often make little/No useful difference.
To compare against "Average Similar" PC's is certainly no Absolute Yardstick to measure by.
But it gives a pretty good & useful Idea.
Typically,,,to Break Out of an Avg Group by any USEFUL amount,,,is usually a matter of going to entire "next level" of PC
#1 Thing to always keep in mind about Computers & their Hardware.
Absolute MAX BEST Possible Today,,
will be on Close-Out Clearance Sale in 6~12 months.
NOBODY ever "gets ahead",,and only Rare Few can even keep up.
A Good,Solid,Reliable PC will serve satisfactorilly for YEARS after it's comparitive performance numbers are "obsolete"
An OLD "Freebie Perf Tip"
Keep Drives DeFragged FREQENTLY,,PC runs better and Defrag gets Quicker the more often ya do it.
Do it 2~3times sequentially each time ya do it.
Keep crap cleaned out,,Cookies,TempFiles,History.
"EveryDay".
I do mine several times daily--mostly outa boredom,,LOL
***'Net Connection settings optimize.....
ALL Windows is known to install Less-Than Optimim settings for Broadband,,,cable/dsl.
PCpitstop has an "auto-fix" which sometimes helps download thruput,,,which gives the sensation of "faster pc"
( If I had a choice of Twice the connection speed,,or Twice the CPU speed------for Me Personally I'd chose BANDWITH without a 2nd thought.
Most of our CPU's are 'adequate for most uses',,,Bandwidth--ya can NEVER get enough.
MANY,MANY Folks would get far better results from Upgraded Net Speed than a faster PC)
http://www.pcpitstop.com/faq/fixes.asp?print=1
http://www.pcpitstop.com/pcpitstop/autofix.asp
Select the "Internet Speed AutoFix" and follow instructions.
Try the "typical Latency Setting"
(there's far more complex Optimizations possible----This is EASY,Quick,Safe,,and "better than nothing" even if it's not IDEAL")
Beats Windows' native/default Dial-Up settings anyway.
Hope any of that helps