ATI HD4800 Review Thread

[Hornet331]

While I can't go into every one of the details, I trust my own results since we are using the proper equipment and tests to properly determine power consumption of the full system (Line conditioner, UPM power meter, etc.). In addition, since I personally spent weeks determining the 3D application which would put the most constant load on the GPU, I can am confident in any numbers we produce.

Many tests you see are highly influenced by the CPU power consumption fluctuating up and down. The trick to properly determining power consumption is to first see which application will properly load the GPU while letting the CPU sit as idle as possible. Then make sure that the program can put an almost constant load on the GPU and its memory with minimal load times in order to get an even testing field.

Finally, the test MUST be run for AT LEAT 45 minutes in order to determine a peak power consumption number. This is due to the fact that many power meters have a sampling rate of about 250ms to 750ms which means that peaks in the power draw may not be logged. That is why you need to have a very long test under constant load; so the power meter can pick up the peaks in consumption even if it misses it the first, second, third and so on time.

I also have to say that it is extremely important to use a line conditioner for power consumption tests. As many of us know, input voltage can fluctuate quite a bit from a household power outlet. This voltage fluctuation can have a pretty large impact on efficiency numbers of power supplies which in turn would influence the numbers generated by any GPU power consumption test.

That is my story, that is how I tested and I am sticking behind my 70W difference statement 100%.

i am not doubting your results, just the variety of results found on the web. If every result would be 50-70W higher then i say ok, but we have results raging from 20-70W. This is kinda hard to swallow.

Maybe your result is the absolut worse case, dependig on what load you used. Since this 2 architekture are quite different, different situations will give different results. E.g. I dare to say that a scene based on heavily texture usage, will produce more heat/power draw on a 280gtx then on a 4870 (80TMUs vs 40TMUs).

hornet you need to stop blindly questioning everything anyone says, SYMTL is a reviewer who is very trusted and clearly has a thorough methodology, his results from both the 280 and the 4870 show the 280 being 70w higher then you just need to accept it

blind following = brainless = not my style
even if hes trusted i have my doubts, as i have with everything. As long as there is such a hugh discrepancy i belive nothing, till i get the chance to test it myself, or far more data if available.