It seem to be only 8 ROPs, else it would not be slower than 9600 GT.
With 55nm wafers @ ~80% costs of 40nm ones and probably higher yields on 55n, I see no real advantage for:
GT216 100mm² vs RV730 140mm²
GT218 57mm² vs RV710 71mm²
(GT215s (~125mm²) die-size competitor is clearly RV740(
According to Anandtech Juniper is 166mm², so Redwood @~100mm² could be a 400SPs part and Cedar migth have the chance to be a bit faster than RV710 while be in GT218s range.
When i first saw the 128bit memory controller i said 8ROPs based on previous desktop DX10 NV architectures.
But if you check the Vantage/3DMark06 scores, a 8ROPs design can't have this performance.
I mean, if the design is like you say 8ROPs/32TUs we have:
GT240 =
8ROPs /
32 TUs /
96SPs /
550MHz core /
1340MHz shaders / 900MHz GDDR5 / 57,6GB/s bandwidth
GT250 =
16ROPs /
64 TUs /
128SPs
700MHz core /
1725MHz shaders / 1000MHz GDDR3 / 64GB/s bandwidth
How is it possible a part like GT250 with 2,5X pixel fillrate with 2,5X texel fillrate and with 1,7X shading speed to be only +6% faster? (5983 vs 5613)
In the mobile space Nvidia had some designs with 8ROPs per 64bit channel, i suspect this will happen here also.
In Vantage the 550MHz GT240 (GDDR5) is around 43% faster than 600MHz 9600GT. (5613 vs 3899)
In 3DMark06 (1280X1024) the
550MHz GT240 (GDDR5) is around 2% faster than
600MHz 9600GT. (9478 vs 9224)
In 3DMark06 (1920X1200) the
550MHz GT240 (GDDR5) is around 8% slower than
600MHz 9600GT. (7629 vs 8313)
I suppose is the memory controller paired with GDDR5 (efficiency, latency, etc...)
But I don't like the Vantage scores (GT240 vs GT250) something is fishy...
If the GT216 is 486 million transistors 100mm2 die size, the GT215 should be at least 725 million transistors which means at least 137mm2 die size at 40nm (i forecast 780 million transistors with 144mm2 die size)
Regarding performance:
Redwood>RV730>GT220
Cedar>RV710>G 210
Even in the case that Redwood is a DX11 RV730 with 64bit memory controller and GDDR5 (lowest possible scenario...) it will be faster than GT220 and the die size would be 93-100mm2.
I 'll post later my predictions.
*EDIT*
Right now the 5750 512MB cost 110$.
GT 220 with 512MB GDDR3 cost 80$.
What price the GT240 DDR3 and GT240 GDDR5 will have?
At least the GT240 GDDR5 will fight against 5750 and will lose handily.