800MHz clock really a 400MHz clock?

[xj0hnx]

I recently purchased a Gigabyte HD 4350, looking at the info in Catalyst Control Center, GPU-Z, and BlackBox all show the memory clock as 400MHz, but it is supposed to be 800MHz. Is this supposed to be like this, or do I have a bad card?

Screenshot

 

[taltamir]

most reporting tools report speed as 1/2 its value in any form of DDR...
DDR is a "trick" to double the bandwidth. DDR2 applies it twice to quadruple it. DDR3 applies it three times to get 8x the "base" bandwidth. as far as the DDR "trick" goes, GDDR3 = DDR2. GDDR4 = DDR2 @ higher clocks, GDDR5 = DDR3 @ higher clocks.

If it was a motherboard I would say it is perfectly normal for it to report half your supposed speed. However I am not SURE this is what is going on here, I assume it is the same, but I am not 100% certain.

 

[yh125d]

It's probably clocking down to save power. run a benchmark with gpu-z in the background and you'll see in the chart that it ramps up

 

[veri745]

I think taltamir is correct. My GPU also reports half of the "effective clock speed", since DDR clocks on both the rising and falling edges of the signal.

 

[Yuriman]

Originally posted by: taltamir
most reporting tools report speed as 1/2 its value in any form of DDR...
DDR is a "trick" to double the bandwidth. DDR2 applies it twice to quadruple it. DDR3 applies it three times to get 8x the "base" bandwidth. as far as the DDR "trick" goes, GDDR3 = DDR2. GDDR4 = DDR2 @ higher clocks, GDDR5 = DDR3 @ higher clocks.

I thought DDR, DDR2 and DDR3 were all 2x, just with progessively looser timings, smaller processes and higher clocks, while (G)DDR5 was 4x.

 

[myocardia]

Originally posted by: Yuriman

Originally posted by: taltamir
most reporting tools report speed as 1/2 its value in any form of DDR...
DDR is a "trick" to double the bandwidth. DDR2 applies it twice to quadruple it. DDR3 applies it three times to get 8x the "base" bandwidth. as far as the DDR "trick" goes, GDDR3 = DDR2. GDDR4 = DDR2 @ higher clocks, GDDR5 = DDR3 @ higher clocks.

I thought DDR, DDR2 and DDR3 were all 2x, just with progessively looser timings, smaller processes and higher clocks, while (G)DDR5 was 4x.

No, taltamir's statement is completely correct. They just don't want to blow your mind by telling you that PC3200, PC2-6400, and PC3-12800 all operate at exactly the same frequency (200 Mhz). The looser timings and higher clocks scenario is how GDDR functions, IIRC.

 

[xj0hnx]

Originally posted by: taltamir
most reporting tools report speed as 1/2 its value in any form of DDR...
DDR is a "trick" to double the bandwidth. DDR2 applies it twice to quadruple it. DDR3 applies it three times to get 8x the "base" bandwidth. as far as the DDR "trick" goes, GDDR3 = DDR2. GDDR4 = DDR2 @ higher clocks, GDDR5 = DDR3 @ higher clocks.

If it was a motherboard I would say it is perfectly normal for it to report half your supposed speed. However I am not SURE this is what is going on here, I assume it is the same, but I am not 100% certain.

This appears this is dead on. Everest reports real clock at 400 (396), and effective clock at 800 (792). And it does look like it clocks back when not in use as it dips to 200 (193) once in a while.

 

[xj0hnx]

What's a bad temp in C for this card? At idle it's mid 50's, during FurRender it hit 64­ºC.

 

[cusideabelincoln]

Those temps look acceptable.

 

[Creig]

Originally posted by: myocardia

Originally posted by: Yuriman

Originally posted by: taltamir
most reporting tools report speed as 1/2 its value in any form of DDR...
DDR is a "trick" to double the bandwidth. DDR2 applies it twice to quadruple it. DDR3 applies it three times to get 8x the "base" bandwidth. as far as the DDR "trick" goes, GDDR3 = DDR2. GDDR4 = DDR2 @ higher clocks, GDDR5 = DDR3 @ higher clocks.

I thought DDR, DDR2 and DDR3 were all 2x, just with progessively looser timings, smaller processes and higher clocks, while (G)DDR5 was 4x.

No, taltamir's statement is completely correct. They just don't want to blow your mind by telling you that PC3200, PC2-6400, and PC3-12800 all operate at exactly the same frequency (200 Mhz). The looser timings and higher clocks scenario is how GDDR functions, IIRC.

Actually, Yuriman is correct. GDDR2, 3 & 4 all have an effective clock speed of 2x the actual clock while GDDR5 runs at 4x effective.