Penello specifies why X1vsPS4 performance difference is overstated

[Pemalite]

petalpusher said:

Do you guys know how to calculate real latency for memory ? it appears there is some misunderstanding here.

I think you're getting a little confused.

CAS Latency tells us how many clock cycles the memory will delay to return data requests, I.E. CL = 8 would mean 8 clock cycles to deliver data whilst DRAM with CL = 9 would take 9 clock cycles to do the same operation.
You can then extrapolate the DRAM's latency, which I outlined in my previous post.

Obviously you have other aspects of DRAM like the RAS to CAS delay which has it's own latency and such.

But it's common knowledge in the PC space that to work out the DRAMS latency is exactly how I laid it out.

I mean this: 20/5500x2000= 7.27 n
Is just wrong, you're not even using the real clock.

The latency would actually be 14.5ns if you had a CL of 20 and a 1375mhz (5500mhz) clock.

CAS Latency/Clock speed (Actual)
Thus 20/1.375 or 20/1375 * 1000

Besides, this is just the DRAM latency, we have zero idea how the eSRAM will affect the latency in the Xbox One, in some cases it might even reduce it, in other cases it will increase it due to the laws of physics.

fallen said:

This is complete nonsense, DDR3 is produced an order of magnitude more (say, 1000 DDR3 sticks for every 10 GDDR5 sticks), so it will always be much cheaper than GDDR5, even say in 5 years 100 DRR3 are produced for every 1 GDDR5. Besides it's not just volume that matter, also production difficulty. GDDR5 is just harder to produce, period, because it's better.

 

Funny.
I never said that GDDR5 wasn't more difficult to manufacture, but maybe you have missed the fact that the PC is transitioning over to DDR4?
Not sure if you were around (Or too young to remember) when the PC transitioned from EDO Ram to SD Ram or SD Ram to DDR Ram or even DDR to DDR2 and the transition from DDR2 to DDR3.
Every single time that occured the prior DRAM technology increased in price as the new DRAM standard became available (Which decreases in price, despite always being more complex than the DRAM version before it), why? Because essentially all production of the older DRAM ceases, demand for the older DRAM remains and thus the issue of Supply/Demand comes into play, prices rise on the older DRAM, prices fall on the new DRAM because people aren't buying it up in droves.

It's all simple logic really and history is there to provide plenty of proof.