Should I go SLI or upgrade CPU?

Sytrus

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Hi, I've been thinking about upgrading my PC for awhile, mainly to increase gaming performance. My current system is:

Nvidia 9800 GT 512mb
AMD Athlon 7750 BE (2.7 dual)
4gb DDR2 800 ram
MSI MS-7390 nForce 570 LT SLI
500w PSU

I run games at 1920x1080, but often see a drop in performance when things get hectic. I only want to upgrade one major component of my PC, so to see the greatest increase in gaming performance, should I upgrade my CPU or run another 9800 GT in SLI with my current one? My major questions are:
1) Would any good AMD CPUs be compatible with my motherboard?
2) Would I have to upgrade my PSU to run two 9800 GT's in SLI?
3) Would upgrading the CPU or graphics show a greater increase in gaming performance based on my system?
And slightly unrelated
4) I tried overclocking my CPU to 3.1ghz by changing the FSB value only, but the system would shut down during intense gaming (the multiplier wasn't unlocked in my bios). Am I doing anything wrong, and is there any way to change the multiplier considering I have a BE cpu?

Thank you for your time.
 
Well going with a newer CPU(limited to the Phenom I series) or adding 1 more 9800GT(Would be very limited to the CPU) is not a good option...And with that setup and playing at 1080p resolution is not a good idea.
For your questions,
1. I wouldn't suggest the old CPUs as a replacement. Still would not offer the expected performance increase.
2. Depends on the quality of the PSU.
3. More than the CPU, the GPU upgrade would have a better effect.
4. Did you try the AMD Overdrive tool ? It has the options to change your multiplier.

Maybe the best option for your is to add another 9800GT in SLI and overclock your CPU to 3GHz...But still it is not sure that you would get a significant performance boost at 1080p because of the CPU limiting factor.
 

Sytrus

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Thanks for the reply!

So you're saying the only CPUs I could upgrade to would be in the Phenom I series, and that the second 9800GT would be somehow tied and limited by the CPU, and that this is related to playing at 1080p? What if I lowered my resolution to 1600x900 instead - would the extra 9800GT have more of an effect then?

Also, I tried the AMD overdrive tool, but it is only for if you have an AMD chipset (I have a nForce 570 LT SLI). Are there any programs I could use besides AMD overdrive to change that multiplier?


Another question about cooling - I have one intake fan on the side of my PC and one fan on the back in addition to the CPU fan, and no space for another fan. Given that when I overclocked to 3.1 the PC shut down when intensely using the CPU, I assume my cooling is not sufficient - how much of a difference would a new fan on the CPU make given that mine is the stock fan?
 
^ Yes the Phenom I would be the possible CPU upgrade for your mobo...
And about lowering the resolution, you would have a +ve effect on the framerates...

Another choice I would say is to sell your 9800GT and spend on a HD 4890, which you can get for about ~$175...So you wouldn't have to deal with SLI issues if any and a HD 4890 will offer comparable performance to 9800GT SLI...And you can also reuse this card in your new build when you build one...

And sorry about the AMD Overdrive...dint notice that you have a Nvidia chipset...I [strike]would[/strike] wouldn't suggest using any other programs other than the Overdrive or the BIOS to change the settings...

The stock cooler should be sufficent for that overclock...I doubt the problem is with the mobo...
 

Tying their own software to their own products,
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ing uncompetitive mother
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ers.
 

Sytrus

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Thanks again.

I know the framerates will increase on 1600x900, but you made it sound like my CPU will be bottlenecking my performance if I use 1080p. Would it still be a bottleneck with the 4890?

Selling the 9800GT seems like a decent idea, I think I may try that. After reading a bit about the 4890, it seems like it has heat issues - will that be a problem given my stock cooling and potential overclocking on the cpu?

So I should just overclock using the BIOS, given that all I can really change is the FSB? And what software could I use to monitor CPU temperature in the background, so I could know how hot it would get up to the point of crashing?

Sorry for all the questions, and thank you again for your patience!
 
^ Yes @ 1080p resolution, the CPU will be holding back the 9800GT SLI...And Yes it would still bottleneck the HD 4890, but like I said you wouldnt have to worry about the SLI issues if any...

And as for the heat issues with the HD 4890, it does get hot but I dont think it would give out more heat than 2 9800GTs that you had previously planned...

Overclocking from the BIOS is the better option...Just increase the FSB in small amount, and then check for stability...
As for CPU temp montiors, try these... - http://www.alcpu.com/CoreTemp/
http://www.techpowerup.com/realtemp/
http://www.almico.com/speedfan.php
 

Sytrus

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Unfortunately not, I'd like to keep my expenses to $200 and under, and I'd have to get a new motherboard to support that.

I'll run some temperature tests today and see what results I get.

A question about processing - will most modern games take advantage of dual / quad cores, or will they still just run on one core? In other words, is all that matters having a high end dual core?
 

Sytrus

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Alright, I upped the FSB to 210 (2.83ghz) and under the prime95 test (for about an hour), the temperature maxed out at 64C. I might raise it to 215, but I'm sort of worried about the temperature - heard about people using the stock cooler and it running fine at 3ghz using the 7750, so I'm wondering if my temperature is unusually high or not.

If I was able to successfully get the CPU up to 3ghz stably, would it still be a bottleneck for running a HD 4890 at 1920x1080? How about 1600x900 - would that reduce the bottlenecking at all?

EDIT: Oh, I checked if the CPU maxed out while playing a game today as well. Only tested with one game (borderlands), which I run at 1920x1080 with everything maxed including 16x AA. Went to an intensive part of the game where my FPS drops to about 25-30, and checked the resource monitor - both cores were running at about 90%.