Motorola MPC7457

[jettredmont]

Re: Re: Re: but...

Originally posted by jettredmont

Mac FSB = 1.085GB/s
AMD FSB = 2.1GB/s
AMD FSB3 = (167MHz * 2 * 8B/cycle = ) 2.672 GB/s
P4 FSB = (133MHz * 4 * 8B/cycle (64bit) = ) 4.256 GB/s
IBM PPC 970 FSB = (900MHz * 8B/cycle = ) 7.2 GB/s

All figures using GB=1,000,000,000 bytes, so will be slightly off from "official" numbers using GB=1,073,741,824 bytes.

Memory bandwidths,. for comparison:

SDR RAM (133MHz) = 1.1 GB/s
DDR RAM (133MHzx2) = 2.1 GB/s
DDR RAM (167MHzx2) = 2.7 GB/s

DDR-III (800MHz) = 6.4 GB/s
DDR-III (1500MHz) = 12 GB/s

And these numbers are, of course, for a single 64-bit data path, not dual memory controllers as one mihgt see on many Intel boards.

 

[barkmonster]

Motorola PDF.

It details the following :

MPC7457/47

0.13µ SOI

MPC7457 ÒLÒ Spec

800Ð1300 MHz, MPX: 166Ð200 MHz, 512K L2

It also mentions that these chips are lower powered than the previous 7455 chips that G4s are using now. and to add fuel to my thoughts about apple moving all the powermac G4 towers onto the 166Mhz motherboard, the MPC7455 now supports 150/166Mhz instead of the previous 133Mhz FSB.

This makes me wonder if that 1.25Ghz chip in the DDR G4s is some kind of hydrid design to bridge the gap between the MPC7457 and the MPC7455.

As well as this, it mentions the MPC7457 won't be shipping till Q2, 2003

It not only doesn't look likely that apple will have faster silicon for a new range on powermacs in early '03 but it looks like the PPC970 and the MPC7457 will be out at the same time. We're at 1.25Ghz now and even with an alteration to the system controller so it can use the full 200Mhz of FSB bandwidth, a dual 1.3Ghz G4 with a 512K L2 isn't going to be something people are going to be interested in when the dual 1.25Ghz model is already out.

MPC7457 fact sheet

If it's already been posted, don't flame me, it's news to me about the official release date and specs of the chip.

 

[Chryx]

Re: Motorola PDF.

Originally posted by barkmonster
As well as this, it mentions the MPC7457 won't be shipping till Q2, 2003
[/i]

Hrmm, 7457 in the emac/imac/ibook, PPC 970 in the Xserve/Powermac/Powerbook ?