Depends - if it's around 1.25 TFLOPS (7770 equivalent), than it's about the same as Xbox 1 to 360 - some 6x. If it's around 7850/7870 equivalent than it's quite the leap, though maybe not as much as should be considering how  long this generation was.

So based on today's rumor a poster on GAF threw up this nice summary.

To which a very reputable poster.. lherre said "Some things here aren't accurate at all but I won't say which ones"

My guess? the GDDR5 as well as some various other RAM and estimations on the GPUs and/or speeds of various things. He's also been known to state that people are expecting too much.

I went ahead and updated thread as we seem to be narrowing down as more and more rumors come out from more reputable sites as well as known devs on gaf hint that various parts are accurate.

Obviously nothing is fact yet, but its looking more and more concrete now.  (also, ratings are not from rumors, but from data from AMD as MSony will change it and we don't know exact yet, I'm just using standard)

Hmm there seems to be a lot of sources saying that both consoles will have some form of extra GPU like SIMD compute hardware, sounds like a Field-programmable gate array. Considering the problems many devs had with the CELL that seems like an odd choice TBH. But I guess if they both have them it will be less of a problem for multiplatform development.

I still think just investing in more powerful GPU and CPU would make more sense than having a 3rd compute unit to worry about for developers tho. Well at least they won't need to worry about SIMD/floating point performance at all. 

A Ubisoft Developer had this to say about the VG247 and NowGamer articles

"In my opinion both machines will be very close, with some details in favor for each one, but I think we will have a ps360 situation again with 2 machines very close.

And some details in the articles are simply wrong"

http://www.neogaf.com/forum/showpost.php?p=46551080&postcount=274

Well, though I was kidding here (of course)

http://gamrconnect.vgchartz.com/post.php?id=5037730

I was under the exact same impression - that FPGA might be something that's inside in addition to traditional GPU. Now, is it for image proccessing or it got something to do with recent (and not so recent) implementations of ray tracing algorithms on FPGAs I can't even guess, but it would be interesting to see something like that inside next gen. As walsnufir also pointed out in other thread, developers bitched about CELL - now, how about programming on circuit level LOL

If anybody is interesting I made a little analyst of how much a CPU/APU/GPU will cost to Sony/Microsoft in the next gen consoles.

http://gamrconnect.vgchartz.com/post.php?id=5044147

People here think the cost of a GPU is over $200 because the product retail is... so wrong.

Ray tracing in a next gen console? Seems like a pointless expense for Sony/MS as I don't see many devs using it or taking full advantage. They'll probably just stick with rasterization and shaders.

if they do use some form of FPGA I would guess that only a few first party titles would really take advantage of it. Most devs would just use some form of middleware to do basic tasks if at all. 

I don't actually think there will be a FPGA in ether tho, that seems a bit out there. I think a cluster of GCN Compute units (possibly with the texture units etc striped out) intended to be used as a big SIMD unit, (tho if they are going to be using 8 Jaguar CPU cores it makes a bit less sense as they are pretty decent at SIMD).

Yes....this is what I was trying to tell SUPERCHUNK.