Vincent Diepeveen (diep@xs4all.nl) on 4/20/11 wrote:
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>I'll have to benchmark it a lot anyway which type of multiplication is fastest.

Also, you can look at the generated code to see if there is more than one mul for each VLIW instruction...

tip: I have looked even knowing the answear...

>Only Volkov mentions it.

I didn't heard that from Volkov... BTW I think you are giving too much credit for him, there are many more people involved, some more involved and for more time...

>It's 4 cycles at both Nvidia as well as AMD GPU's before for simple instructions your result is available.

It's for 4 cycles for the instruction to be issued for all lanes, in ATI case it's more 4 cycles for another wavefront to issue instructions and maybe for the first wavefront to execute then finally more 4 cycles to issue the next instruction, maybe a more correct number would be 16 because only after 16 cycles the result would be avaliable, anyway, this doesn't matter.

BTW, in nVidia case starting on Fermi it's just 2 cycles to issue the wrap, the number of cycles to execute vary.

>An instruction can take 4 such as trivial 'add', but you don't have your results
>until 5th cycle.

Until the 9th cycle on AMD hardware.

>Any claim of determinism shows your ignorance.

Same contitions, same results = deterministic

Almost same conditions different results and a conclusion = you are an idiot.

>Does power7 only have a single aircooled microtiny fan that has to cool 400+ watt,
>from which at least a 100+ over specs of the pci-e?

It's 250W if I remember correctly, for z196 it's even more, draw your own conclusions.