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Bulldozers 'Flex FP' Superior to Sandy Bridges FPU?

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October 26, 2010 2:33:46 AM

Im not saying this is a fact, but it may be the case according to this recent blog from JF:
http://blogs.amd.com/work/2010/10/25/the-new-flex-fp/
Read the whole thing, theres alot of info.
Specifically this part:
"One of these new instruction set extensions, AVX, can handle 256-bit FP executions. Now, let’s be clear, there is no such thing as a 256-bit command. Single precision commands are 32-bit and double precision are 64-bit. With today’s standard 128-bit FPUs, you execute four single precision commands or two double precision commands in parallel per cycle. With AVX you can double that, executing eight 32-bit commands or four 64-bit commands per cycle – but only if your application supports AVX. If it doesn’t support AVX, then that flashy new 256-bit FPU only executes in 128-bit mode (half the throughput). That is, unless you have a Flex FP."

Does this mean Bulldozer's FPU will be faster than Sandy Bridges in non AVX mode?
a b à CPUs
November 5, 2010 3:30:43 AM

Faster: IDK, larger: YES!
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a b à CPUs
November 5, 2010 4:07:27 AM

I guess, but if BD gets it...BA-BOOM!
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November 8, 2010 11:49:46 PM

Well BD seems really different, and i dont think we can use what we know to make accurate performance predictions.
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a b à CPUs
November 9, 2010 12:54:14 AM

We cant make predictions, squat!
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November 9, 2010 2:35:08 AM

Eh its fun though! Personally im hoping BD can be another Athlon 64. And also i wouldnt assume its only going to have 8 cores (4 modules) max for desktop. It could be like Thuban which came out of nowhere basically and managed to fit those 6 cores onto the chip. And JF mentioned many times that having another core per module doesnt really increase die size too much.
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a b à CPUs
November 9, 2010 3:15:07 AM

Enlighten me on the adventures of the Athlon 64. Was is an x86 64 CPU? 2003? A golden day for AMD? If it is, I'm with ya'!
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