Bottlenecking HD 5870?

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Graphxproblems

Weaksauce
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I currently have 2 X1950 XTX cards in Crossfire, 3 GB of RAM, and a Core 2 Duo processor clocked at 2.66 GHz. I want to upgrade to a Radeon HD 5870 (only one card, no Crossfire). However, will my processor bottleneck the system so the 5870 won't work to its potential when running games? Thanks.
 
Graphxproblems said:
Thanks for clearing that up. But will the CPU be bottlenecked so badly that there would be no reason to buy the 5870 without getting a new CPU as well?
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Why not just get the 5870 AND overclock your CPU?

That is, unless you have an OEM box that doesn't have BIOS features that allow overclocking.
 
cyclone3d said:
Why not just get the 5870 AND overclock your CPU?

That is, unless you have an OEM box that doesn't have BIOS features that allow overclocking.
Click to expand...

Unfortunately, I think that's the problem. Something is wrong with my BIOS so that it doesn't allow me access to all the overclocking features. I can change the CPU speed by altering the "Burn-In Percentage" which increases the FSB but if I get above 2.66 GHz (I have an e6600) I start experiencing crashing. Could this possibly be the answer to the problem? This is a post I just found about overclocking on my motherboard, an Intel 975XBX:

"Final tip based on my experience: I had not realized that you need to underclock your memory to fully overclock the CPU via the FSB. I have Corsair 800 MHz memory. As I increased the FSB, it increased both the CPU and the memory speed, and pretty quickly the memory was maxed out. This meant that I could barely overclock the CPU via the FSB without the memory giving me problems.

To fix it, I went into the BIOS and manually set the memory to operate at 533 MHz. As the 975XBX/Bad Axe motherboard has a basic FSB speed of 266 MHz, setting the memory at 533 MHz generates a 1:1 FSB to memory ratio (as the memory is DDR, doubling the basic FSB speed give you the memory speed you need if you are trying to achieve a 1:1 ratio). As the memory is now underclocked, I can raise the FSB (and thus the CPU speed) quite significantly without maxing out the memory."
 
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Graphx:

To take full advantage of the 5870, you will need to whip out the old CC and buy some new parts. I put a 5850 in my C2D (E6750 @2.66) while I was waiting on my new I7 build parts, and while it did make some difference, it was nothing like the performance bump I got when pairing the 5850 with an I7 920.

I know there will probably be people here that want to argue that point, but just telling you what I saw during the upgrade process.

Sorry to be a buzz kill....
 
I know it will run a lot better with some kind of quad-core, but I'm pretty happy with the performance I'm getting out of my current set-up, so I don't need a massive improvement. If I can just OC my current processor to 3 GHZ or something like that and get the new card, that should be enough for me. Did you overclock your C2D above 2.66GHz?
 
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Hey, whatever makes you happy. That new stuff will always be available and get a little cheaper as time goes by.

Hope you can find a 5870 soon. It seems like the availability is getting worse rather than better.
 
Graphxproblems said:
I currently have 2 X1950 XTX cards in Crossfire, 3 GB of RAM, and a Core 2 Duo processor clocked at 2.66 GHz. I want to upgrade to a Radeon HD 5870 (only one card, no Crossfire). However, will my processor bottleneck the system so the 5870 won't work to its potential when running games? Thanks.
Click to expand...

Here is what I can tell you from a REAL WORLD experience.
I had(one died, unrelated to this experience) (2) 5870's in Crossfire. I have an i7 920 and was running it initially at stock speed (~2.6GHz). I loaded up Crysis:Warhead to try out these new video cards. I had it set to just below extreme settings. There was still slight stutter on certain cutscenes and gameplay. I then overclocked my 920 to 4.2GHz STABLE and the stuttering was ABSOLUTELY gone from Crysis(as well as a few other games tested. but most prominent on Crysis). So I can without a doubt tell you that 5870's benefit a lot from the CPU.

I did not change anything except for the CPU speed and it helped all my problems on Crysis even with (2) 5870's. The stutter had nothing to do with the Crossfire setup or drivers. It was fixed immediately with the bump in CPU speed.
 
Being a budget minded upgrader here's my thoughts. I don't know what your upgrading schedule is, but being as you have an oem box I'm going to assume you're not upgrading your entire system every 4-6 months. I say if you have the funds for the 5870, get it. Then save up and in a few months or so upgrade the cpu and possibly motherboard.
The issue I see with so many bottlenecking questions is people being concerned about not getting optimal performance. Well when you buy a new release of any part it's going to be faster than what you have in your other parts, unless you build an entire new system. There will always be a bottleneck somewhere in your system. So unless you have the budget to build new systems every 6 months you may as well lay out a plan for upgrade. What's important for you to replace first and go from there.

another issue here is does your current system have the power supply to support a 5870?
 
TechloGoblin and bigbadgreen, thanks for your responses. My power supply unit is 700 watts. Also, I got my CPU up to 3.02 GHz stable. All I had to do was underclock the memory, because the only way for me to overclock the CPU was to increase the FSB speed which was maxing out the RAM speed and causing crashes. I couldn't make it to 2.73 GHz before, now I'm pretty sure I'll be able to make it to 3.20GHz or more.
 
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