Overclocking

As with the 7800 GTX, how the 7800 GT overclocks (beyond the factory clock) is something that we'll be looking at closely. Many of the 7800 GTXs had impressive factory overclocks, and the GT series looks to be no different. As we mentioned before, the XFX GeForce 7800 GT comes out of the box with a factory overclock of 450MHz core and 1.2GHz memory clocks. We were curious to know if we would be seeing the same core clock scaling that we saw with the GTX; specifically, if the performance increases were between the same frequencies.

Just to review, here is a brief explanation of what we saw happening with the 7800 GTX when adjusting clock speeds. Basically, we were seeing plateaus where consecutive core clock speeds had barely any impact on framerates (only a few tenths of a frame per second), then intermittent jumps up in performance between frequencies (i.e. between 472MHz and 473MHz). And because you get increasingly longer "plateaus" of minimal increase as you raise clock speeds, we've shown that this can cause for some confusion about how much faster each of the vendors' factory- overclocked 7800's really are.

After running some tests with Splinter Cell: Chaos Theory, we found that the frequencies didn't match up with what we saw with the 7800 GTX. We didn't see any jump in framerate between 472MHz/473MHz as we did with the GTX; instead, jumps occurred between 461MHz/462MHz and 477MHz/478MHz. We will be looking into this more closely in the next 7800 GT article, and hopefully, we can shed some more light on NVIDIA's frequency selection issues.

Interestingly, while attempting to overclock this card (the XFX GeForce 7800 GT), we managed to reach a core clock speed of 477MHz, which is actually a higher core speed than both the reference 7800 GTX (430MHz) and even some of the factory overclocked 7800 GTX's that we tested. This is equivalent to the performance that we would have seen at a 462MHz overclock. We did this without any special cooling systems, and the overclocking potential of these cards could be yet one more reason to choose the GT over the GTX right now. Buying a cheaper card and squeezing more performance out of it is maybe a better option than spending the extra money. But we have to say, as always, overclocking is risky and varies between cards, so if you plan on doing some overclocking yourself, we recommend paying very close attention to the warranty offered by the manufacturer.

The Card Performance Tests
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  • JNo - Wednesday, August 31, 2005 - link

    "We'll be looking at how the different 7800 GTs compare to each other as we review them, so be on the lookout for another 7800 GT article soon. We want to make these reviews as helpful as possible, so any comments or suggestions that you have regarding tests, cards, or anything else, please let us know."

    I second (or third or fourth...) the call for a round up review. I don't want to have to read 5-7 separate reviews of 7800GT cards just to determine the best one. I want you to tell me! Obviously with graphs summing up different characteristics (overclocking, noise, plateau characteristics, $ per FPS etc) so I can make a different choice if the emphasis on my individual needs differs...
    Reply
  • bob661 - Wednesday, August 31, 2005 - link

    This is the first time I've seen some value in OCing a video card. Near 7800GTX performance for $100 less. Reply
  • Avalon - Wednesday, August 31, 2005 - link

    Seems like at 1600x1200, an overclocked GT is right up there with a GTX. I would like to have seen higher resolution benchmarks of the GT overclocked at 462/1.2, so we could see how much ground the GT lost, if any. For all you 2005/2001FP owners out there, grab the GT model, and forget about the GTX. $100 isn't worth 1% boost in performance. Reply
  • Houdani - Wednesday, August 31, 2005 - link

    But, but, but ... the noise!

    You are correct, financially the GT is a better choice than the GTX -- just not this particular card. Who at XFX chose that fan? It's a screamer!
    Reply
  • Ozz1113 - Wednesday, August 31, 2005 - link

    Im sure there will be aftermarket cooling solutions out real soon to bring the db's down.

    Oh, I use water =D
    Reply
  • Scarceas - Wednesday, August 31, 2005 - link

    I too would like to have seen comparison to a 6800Ultra and a Radeon x850 Reply
  • fishbits - Wednesday, August 31, 2005 - link

    quote:

    We've already looked at how the 7800 GT ranks alongside the GTX and other graphics cards, including dual-card SLI setups, and you can take a look at the review here.


    Third paragraph into the article (with EZ-Klik hyperlink technology!). No it doesn't bench every possible video card, but more than enough to figure out where the GT fits in. The 6800 Ultra you said you wanted to see is right there.
    Reply
  • Furen - Wednesday, August 31, 2005 - link

    OMG, make it stop... Reply
  • Houdani - Wednesday, August 31, 2005 - link

    Agreed! I much prefer the roundups over these single vendor reviews. A /short/ summary of all the vendors is more than adequate, contained within the roundup article. Reply
  • 4AcesIII - Wednesday, August 31, 2005 - link

    What happened to the group reviews, they missed the Leadtek 7800GTX and now they probably won't so they can do XFX and EVGA again only maybe a MSI to make it look good. Sheesh why do I even come here anymore? Reply

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