HD 4770 Previews/Reviews

[ToTTenTranz]

The HD4850 would be about 10-15% slower if it had GDDR5 instead of GDDR3 - i'd say it's relevant

erm... no.

Those graphs are comparing GDDR3 with GDDR5 at half the speed of GDDR3. For example, in that case it's 993Mhz GDDR3 versus 497Mhz GDDR5. However, it would be pretty stupid for the HD4850 to have 500Mhz GDDR5. If the HD4850 had GDDR5, it would be 750Mhz minimum.

I don't quite get your point. I'm just arguing that GDDR5 is about 10-15% slower than GDDR3 given the same bandwidth.

No, it's given the same.. let's call it the same "single data-rate clockspeed".

It's always been like that. DDR was already slower than SDR if DDR was underclocked to the half of the speed of SDR.

What if the 4750 matched the 9600GT in cases where bandwidth limitations weren't that severe?


I heard that was their target previously, 9800 for the highend version and 9600 for the GDDR3. Granted, the lake of salt is right... there.

Well.. ATI has launched their share of highly bottlenecked cards before, like the HD4650 DDR2 (phail...).
Or even worse: the FirePro V3750, which is a 320sp RV730 with a 64bit memory controller (yeah, the original 320sp R600 had 8x more bandwidth).