OK, I found interesting sentences in the PC Perspective preview
(also published on November 9th):Update
: The author corrected the mistake.
That graphics portion is made up of 2 x 80 unit SIMDs (incorrect; 1 SIMD in Cedar core = 40 stream units), so it has a grand total of 160 stream processors (incorrect; 2 x 40 = 80 stream processors).
Some other previews on the internet incorrectly listed the number of stream units in their articles (yes, they are correct). It is in fact 160 (80) stream units for the integrated graphics, which is amazing considering that only a few short years ago the high end HD 2900 XT featured only double that number (320).
Words in red letters are my comments. The trick is1 SIMD
in HD 5900/5800/5700/5600/5500 Series GPU = 16
Thread Processors = 80 Stream Cores1 SIMD
in HD 5450 GPU = 8
Thread Processors = 40 Stream Cores
(the number of Thread Processors in the SIMD engine is reduced in half)
Perhaps the author confused them. Here are figures of SIMD (the black rectangle)
and Thread Processor (the white rectangle
; each consisting of 5 Stream Cores
, called VLIW5 [Very Long Instruction Word 5]
) in HD 5570 and HD 5450.
HD 5570 (5 x SIMD, 80 Thread Processors, 400 Stream Processors):
HD 5450 (2 x SIMD, 16 Thread Processors, 80 Stream Processors):
BTW it is a bit surprising that some hardware review sites (like PC Perspective
; the author is Ryan Shrout) said HD 5450 has *one* SIMD unit with 80 stream processors.
This is wrong. HD 5450 has *two* SIMD units, each with 40 stream processors, 80 stream processors in total.