![[IMG]]()
We've recent mis-information flying around, I' thought I'd *try* to 'normalise' available metrics for both systems to give an apples to apples high level architectural comparison so you can make your own conclusions.
I'm only going to provide 'normalised' total system metrics compared to the above image as this is all we can compare across both systems at the moment until more details are released.
1) Shader ops
Shader ops in isolation are not very meaningful, but I'll try to compare to the above
Earlier discussion on a shader op,
http://www.beyond3d.com/forum/viewtopic.php?t=23169
-PS3
claimed PS3 ~ 100 billion shader ops per second
Cell ~ 8 shader ops per cycle (7 SPU + VMX)
8*3.2GHz ~ 25.6 billlion shader ops per second
RSX ~ 136 shader ops per cycle
136*0.55GHz ~ 74.8 biilion shader ops per second
total= 74.8+25.6 ~ 100 billion shader ops per second
PS3 ~ 100 billion shader ops per second
-X360
xGPU ~ 96 Shader ops per cycle
96*0.5 GHz ~ 48 billion shader ops per second
xCPU
6*3.2~ 19.2 billion shader ops per second (3 VMX + 3 FPU)
total= 48+19.2~ 67.2 billion shader ops per second
X360 = 67.2 billion shader ops per second
2) Dot products
-PS3
claimed PS3 ~ 51 billion dot products per second
Cell ~ 8 per cycle (7 SPU + VMX)
8*3.2GHz~ 25.6 billion dot products per second
RSX ~ 51-25.6 ~ 25.4* billion dot products per second
* deduced from claim
PS3 ~ 51 billion dot products per second
-X360
claimed xCPU ~ 9 billion dot products per second
xCPU~ 3 dot products per cycle (3 VMX)
3*3.2 GHz ~ 9.6 billion dot products per second
xGPU ~ 48 dot products per cycle (48-way vec4)
48*0.5 GHz ~ 24 billion dot products per second
total ~ 9.6 + 24 ~ 33.6 billion dot products per second
X360 ~ 33.6 billion dot products per second
3) TFLOPS
Some theory to the madness,
http://www.beyond3d.com/forum/viewtopic.php?p=523362#523362
PS3 ~ 2 TFLOPS
X360 ~ 1 TFLOPS
Cannot derive these figures but both companies have used peak total system flops which cannot be compared with single/double precision programmable flops. On their own they do not mean much but they are apples to apples between X360 and PS3, IMHO.
4) Memory
FYI, earlier bandwidth discussion,
http://www.beyond3d.com/forum/viewtopic.php?t=23011
I'm going to normalise bandwidths and memory so that they are more comparable. What I mean by this is that 25 GB/s access to 256 MB is equivalent to 50 GB/s access to 128 MB or equivalent to 100 GB/s access to 64 MB etc etc...and assuming the same latencies apply...
Currently AFAIK,
* The 256 GB/s is not a physical inter-connect bandwidth, it's the intra-EDRAM module bandwidth *within* the EDRAM module. The inter-connect bandwidths between xGPU and the EDRAM module are 32 GB/s write and 16 GB/s read. These are the numbers from the 'leak' and the 256 GB/s is the 'effective' bandwidth. Since both systems will use compression/ bandwidth saving techniques, I'm using physical inter-connect bandwidth to a better apples to apples comparison.
Starting point,
[X360: CPU<==21.6 GB/s==>GPU]----48 GB/s* ----[10 MB]
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22.4 GB/s
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[512 MB]
[PS3: CPU<==35 GB/s==>GPU]----22.4 GB/s ----[256 MB]
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25.6 GB/s
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[256 MB]
>>>>>memory b/w and memory amounts normalise for PS3 to match X360<<<<<<<<
[X360: CPU<==21.6 GB/s==>GPU]----48 GB/s* ----[10 MB]
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22.4 GB/s
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[512 MB]
[PS3: CPU<==35 GB/s==>GPU]----48 GB/s----[119.5 MB]
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22.4 GB/s
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[293 MB]
>>>>>FSB, CPU-GPU normalise for X360 to match PS3<<<<<<<<
[X360: CPU<==35 GB/s==>GPU]----48 GB/s* ----[10 MB]
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22.4 GB/s
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[316 MB]
[PS3: CPU<==35 GB/s==>GPU]----48 GB/s ----[119.5 MB]
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22.4 GB/s
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[293 MB]
It's now easier to compare physical bandwidths and memories across both PS3 and X360 to give a better sense of data flows and data access. If the 256 GB/s* effective bandwidth of the EDRAM replaces the 48 GB/s* physical bandwidth, then it's easier to map and compare both architectures data flows IMHO.
[X360: CPU<==35 GB/s==>GPU]----256 GB/s* ----[10 MB]
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22.4 GB/s
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[316 MB]
>X360 normalised total system + VRAM = 326 MB
[PS3: CPU<==35 GB/s==>GPU]----48 GB/s ----[119.5 MB]
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22.4 GB/s
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[293 MB]
>PS3 normalised total system + VRAM =412.5 MB
5) Summary
So normalising and apples to apples figures for the above total system spec for PS3 are,
PS3 vs X360
PS3 ~ 100 billion shader ops per second
X360 = 67.2 billion shader ops per second
PS3 ~ 51 billion dot products per second
X360 ~ 33.6 billion dot products per second
PS3 ~ 2 TFLOPS
X360 ~ 1 TFLOPS
PS3 normalised total system + VRAM =412.5 MB
X360 normalised total system + VRAM = 326 MB
Normalised,
Code:
[PS3: CPU<==35 GB/s==>GPU]----48 GB/s ----[119.5 MB]
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22.4 GB/s
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[293 MB]
[X360: CPU<==35 GB/s==>GPU]----256 GB/s* ----[10 MB]
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22.4 GB/s
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[316 MB]
This is as close an apples to apples comparison that can be made with available info.
No flames please, if they're are any mistakes or inconsistencies, then please let me know and I'll amend the data above. Also, I'm assuming equal efficiency across both systems with compilers, code etc.
I'll re-iterate, it's a peak, apples to apples comparison, or as close to what we can get with available info at the moment without isolating any single components like CPUs, GPUs, bandwidths, total RAM etc...it's a total system vs system.
IMHO, they'll both have their strenghs and weaknesses and will both be great systems but the PS3 has overall balance and power suited to a games console.
![[IMG]](http://www.watch.impress.co.jp/game/docs/20050519/ps3_r02.jpg)
