Just to kill time, last nite I decided to underclock my 6600GT to vanilla 6600 levels. I reduced the speed from 574/1174 to 475/615. I have found that most standard 6600 cards can be overclocked & remain stable at these frequencies up from stock of 300/550. I then proceeded to run my usual set of benchmarks to see just how much would be the performance difference. Read as... (Benchmark : Score@574/1174, Score@475/615)... 3DMark05 : 3619 , 2532 3DMark03 : 8546 , 6113 So far so good as far as the synthetic benchmarks r concerned. But the results of the following game benchmarks have me in shock... D3 timedemo1 : 45.7fps, 43.6fps HL2 d1_canals_10 timedemo : 53.45fps, 48.81fps COR Mainframe1 2++ : 34.04fps, 31.78fps COR Mainframe1 2.0 : 66.97fps, 59.12fps The gaming performance of my 6600GT is near identical at speeds of 574/1174 & 475/615!!. I know that my P4 2.4 CPU is a bottleneck for the GT but even allowing for that, should there not be a noticeable difference in the scores? I'am now starting to doubt the utility of my investment. I had the choice of buying an XFX 6600 256MB card at nearly half the price but I chose the faster frequencies over the extra memory. But my little experiment has made me think that maybe I would have got similair performance in games with the vanilla version & in the process would have saved a bundle & got myself 256MB of video ram to boot. What do u gentlemen think? Responses anxiously awaited & thanx to everyone in advance for ur time & valuable thoughts.
the normal 6600 and the 6600gt use the same cores, the main difference is that the 6600gt uses gddr3 memory, while the 6600 uses normal ddr, so the memory on the gt will clock higher. the gt is definitly worth the cost over the normal, even though it only has 128mb.
kwak is right, the difference is the memory. my brother has a 6600 and he can get his gpu just as high a my 6600gt.
Overclock that 2.4 pressy and you'll see the Delta increase slightly more. Instead of 4-8fps difference you may see 6-12 which is quite a bit faster.
a ddr3 mem @ 615Mhz will still perform better than a ddr OC'ed to 615MHz...... The effective bandwith of a ddr3 mem is thrice that of ddr at any given frequency(theoritically).....hence the data transferred at 615Mhz by a ddr3 ram module will still be better than a ddr one..... As for the 3dmark scores most of the difference were due to the 100MHz less core frequency..... In the game tests compare your GT scores with a real non-gt ...the difference will be more.....i used to have a 6600 and used to get a lot less even after OC......the gt rocks
kwak i was noticing you had a regualr 6800 how did you get your clocks so high and is that a 6800 or 6800gt do you have ddr3 or ddr1 and what did you use to overclock it that high because that is a sweet score also did you change the lod bias or anything else to get that score
this is the asus v9999gamer edition, its a 6800nu with 256mb of ddr3 memory. i used rivatuner to unlock the pipes and vertex, and to oc the card. No changes to lod bias, the only tweaks was driver profile to high performance and shutting down as much processes as possible, excluding zonalarm and avg antivirus. im really happy with my scores, and my proc really helped, 3d05 went from 5980 with an athlon xp @ 2500 to what i have now, exact same graka speeds.
Nope. The effective memory bandwidth for all DDR (inc. DDR, DDR2, GDDR2, GDDR3) is the same at a given clock.
That depends if you are talking about the actual or effective clock speed. it is true for the effective clock speed, but not for the actual.
GDDR3 would still not give you three times the memory bandwidth than DDR at the same clock. The 5700 Ultra has 128-bit GDDR2 clocked @ 450MHz (700MHz effective) = 14.4GB/s memory bandwidth. The 9800 SE has 128-bit DDR clocked @ 450MHz (700MHz effective) = 14.4GB/s memory bandwidth. As you can see, the 5700 U has the same amount of bandwidth as the 9800 SE and not double. My figures for bandwidth can be found just about anywhere on the web, such as: http://users.erols.com/chare/video.htm You said: ... which is wrong. The quote you gave from wikipedia does not contradict what I said. With the example used in this thread of the 6600GT/6600: 6600GT - 128-bit GDDR3 clocked @ 500MHz (1000MHz effective) = 16.0GB/s memory bandwidth 6600 - 128-bit DDR clocked @ 250MHz (500MHz effective) = 8.0GB/s memory bandwidth For your statement I quoted to be correct, the 6600GT would need to have 6 times the memory bandwidth than the 6600, which it does not.
I don't know what you mean by that. There is no point where we would need to divide 1000 by 3 in the calculation(s) I used. The 6600GT has twice the clockspeed, and so double the bandwidth of the 6600. The GDDR3 doesn't by itself increase the bandwidth, it just allows for higher clockspeeds compared to DDR since it was manufactured on a smaller process. GDDR3 is double data rate and not triple data rate. People easily get confused by the arbitrary '3' nomenclature that does not mean triple data rate or anything of the sort. Although there are other inherent benefits to using GDDR3, none increase the memory bandwidth over DDR. Therefore, shravan was correct in his assumption that underclocking his 6600GT could provide similar memory bandwidth to a 6600. This is pretty basic stuff to an enthusiast.
GDD3 just means people who like to OC like mad, can do so with more overhead period. If it was triple data rate, it wouldn't be worth even comparing a 6600GT and 6600, since the difference would be rediculous. It's almost like a Turbo on someone's car, the Turbo just allows you to push the engine to the next level, but the engine stays inherently the same as a non-turbo engine.
