ATI Radeon X800 GT: A Quality Mid-range Solution

[lifeguard1999]

Article

I know that this is suppossed to be about the X800 GT, but why does the 6600GT beat or tie 6800 in so many benchmarks?

The 6600GT wins all the benchmarks vs. the 6800 in BF2.
In Doom3 it is a tie w/o AA turned on; with AA turned on the 6800 wins.
In Everquest2 it is a tie up until 16x12-4xAA when the 6800 wins.
In HL2 the 6600GT wins up until 16x12-4xAA when the 6800 wins.

 

[tvdang7]

yea pretty crazy huh? thats quite a powerful 6600gt thast 6800 would only be good if u unlock the pipes and try to overclock to gt speeds in my opinion.....

 

[blckgrffn]

Because the 6600GT has more fillrate than the 6800, thats why. It is also wins the highres+eyecandy stuff for the same reason the X800GT pulls ahead in some cases there too, it has much more memory bandwidth. # of pipes doesn't matter nearly so much as fillrate.

🙂

 

[ZobarStyl]

Originally posted by: blckgrffn
Because the 6600GT has more fillrate than the 6800, thats why. It is also wins the highres+eyecandy stuff for the same reason the X800GT pulls ahead in some cases there too, it has much more memory bandwidth. # of pipes doesn't matter nearly so much as fillrate.

🙂

That's not really it...the fillrate between the two is incredibly close, with the GT being slightly higher...the true reason lies with the 900 mhz GDDR3 on the 6600GT vs the 700 mhz DDR on the 6800; the RAM is likely the key difference in the 6600GT taking the lead over 6800 in a lot of cases.

 

[hitmanx2]

Originally posted by: ZobarStyl

Originally posted by: blckgrffn
Because the 6600GT has more fillrate than the 6800, thats why. It is also wins the highres+eyecandy stuff for the same reason the X800GT pulls ahead in some cases there too, it has much more memory bandwidth. # of pipes doesn't matter nearly so much as fillrate.

🙂

That's not really it...the fillrate between the two is incredibly close, with the GT being slightly higher...the true reason lies with the 900 mhz GDDR3 on the 6600GT vs the 700 mhz DDR on the 6800; the RAM is likely the key difference in the 6600GT taking the lead over 6800 in a lot of cases.

actually ddr1 has a lot tighter timings than ddr3, the 700mhz ddr1 shouldn't be a lot slower than 900mhz ddr3, similar to the cirumstance when 2-2-2-5 ddr 400 doesn't really fall behind when compared to 3-4-4-8 ddrII 533. in last gen, 5700ultra used ddrII and ddr3 memory and but it was still inferior to 5900xt. Besides, 6800 has 256bit mem interface, which is suppose to be faster, The fillrate are rounghly the same (12x325=3900 compare to 8x500=4000), maybe somehow the 6600gt has a better architecture. It is really hard to understand a card with 128bit mem interface, 4000 fillrate, a slightly higher mem clock with loose timing that beats/ties a card with 256bit mem interface, 3900 fillrate, a slightly slower mem clock with tighter timing.

 

[M0RPH]

Originally posted by: lifeguard1999
Article

I know that this is suppossed to be about the X800 GT, but why does the 6600GT beat or tie 6800 in so many benchmarks?

The 6600GT wins all the benchmarks vs. the 6800 in BF2.
In Doom3 it is a tie w/o AA turned on; with AA turned on the 6800 wins.
In Everquest2 it is a tie up until 16x12-4xAA when the 6800 wins.
In HL2 the 6600GT wins up until 16x12-4xAA when the 6800 wins.

I don't know why this is but TomsHardware VGA charts has shown this for some time now. I always thought his charts were wrong because they show the 6600GT beating the 6800 in almost all the benchmarks. Now Anandtech confirms this. There's no reason now for anyone to pay more for a 6800 over a 6600GT.

 

[fliguy84]

Originally posted by: ZobarStyl

Originally posted by: blckgrffn
Because the 6600GT has more fillrate than the 6800, thats why. It is also wins the highres+eyecandy stuff for the same reason the X800GT pulls ahead in some cases there too, it has much more memory bandwidth. # of pipes doesn't matter nearly so much as fillrate.

🙂

That's not really it...the fillrate between the two is incredibly close, with the GT being slightly higher...the true reason lies with the 900 mhz GDDR3 on the 6600GT vs the 700 mhz DDR on the 6800; the RAM is likely the key difference in the 6600GT taking the lead over 6800 in a lot of cases.

well the core plays a role too. 325MHz on the 6800 vs 500MHz on the 6600gt. btw, since the review is based on pcie cards, the 6600gt memory speed should be 1000Mhz =)

 

[Dribble]

Originally posted by: ZobarStyl

Originally posted by: blckgrffn
Because the 6600GT has more fillrate than the 6800, thats why. It is also wins the highres+eyecandy stuff for the same reason the X800GT pulls ahead in some cases there too, it has much more memory bandwidth. # of pipes doesn't matter nearly so much as fillrate.

🙂

That's not really it...the fillrate between the two is incredibly close, with the GT being slightly higher...the true reason lies with the 900 mhz GDDR3 on the 6600GT vs the 700 mhz DDR on the 6800; the RAM is likely the key difference in the 6600GT taking the lead over 6800 in a lot of cases.

6800 has 256 bit memory bus but 6600GT only has 128 bit one so 6800 has lots more memory bandwidth.

 

[orangat]

The 6800 doesn't have lots more memory bandwidth. Its slightly less than 6600GT. The 6600GT's memory is clocked higher.

 

[Dribble]

256 bit bus is twice 128 so double the bandwidth numbers in comparison to 6600GT. If you want the exact figures check out the nvidia web site - 6800 has 22.4 Gig/sec bandwidth, 6600GT only has 14.4 Gig/sec agp, or 16 Gig/sec for slightly faster pci-e version.

 

[coldpower27]

Not true assuming your using the default PCI-E versions of the cards.

The 6800 Vanilla should have a 20% advnatage in memory bandwidth in comparison to the 6600 GT due to 256Bit Memory Interface vs 128Bit on the 6600 GT.

PCI-E

1000MHZ x 128Bit / 8 = 16.0 GB/s Memory Bandwidth

600MHZ x 256Bit / 8 = 19.2 GB/s Memory Bandwidth

On AGP the differences between 6600 GT & 6800 Vanilla are greater, as some 6600 GT are clocked at 900MHZ as per reference design, with some at 1000MHZ or greater, vs all 1000MHZ on PCI-E, plus the 6800 Vanilla reference clock is 700MHZ on AGP vs the slower 600MHZ on PCI-E. Hence why the differences are so close possibly on PCI-E.

900MHZ x 128Bit / 8 = 14.4GB/s Memory Bandwidth

700MHZ x 256Bit / 8 = 22.4GB/s Memory Bandwidth

There is potentially over a 50% difference of memory bnadwidth on AGP.

 

[compgeek89]

Its only the PCIe 6800, the AGP thoroughly whips ths 6600 GT, the PCIe is using the NV41 core instead of the NV40... which sucks.

 

[blckgrffn]

Originally posted by: compgeek89
Its only the PCIe 6800, the AGP thoroughly whips ths 6600 GT, the PCIe is using the NV41 core instead of the NV40... which sucks.

I wouldn't say it sucks, many people seem to get ~450 mhz out of them, which is pretty good by my book 😉

I think that it was foolish of Nvidia to release two parts so close in performance at two distinct price points, but on the other hand I enjoy unlocking those AGP 6800's 🙂