970 Motherboard and Chip Delivery?

[AidenShaw]

Re: We're both right/wrong

Originally posted by barkmonster
I'm well aware of this but I've also read that it's awkward to implement a 36bit address space with a 32bit cpu. (read it on here not on a technical site like arstechnica or anything like that).

It's not difficult for an operating system to control >4GiB, and let multiple <4GiB processes use memory at the same time. Of course, each process is 32-bits, but together a number of large processes can use 16, 32 or up to 64GiB of memory.

It is possible, but as you say quite awkward, for a 32-bit program to remap memory into different windows. This can let it address more than 4GiB over time, even though at any instant it is limited to 4GiB. This isn't really important any more - most of the programs that needed to do this have migrated to true 64-bit computers.

Also, I know that not all G4s support the 36bit address space, only the G4+ cpus can. Even then, only the real (phsyical ?) address space is 36bit, the virtual address space is still only 32bit. The G4 as a whole (as in ANY G4 past or present) isn't capable of using more than a 32bit address space.

You're right - on the Moto pages http://e-www.motorola.com/webapp/sps/site/taxonomy.jsp?nodeId=03C1TR04670871 the MPC7410 is 32-bit, the MPC7441 and higher are 36-bit.

Moto does claim that even the G3 can support 4 PiB of virtual memory (52-bit virtual addressing), but that's using a segment addressing scheme.

 

[AidenShaw]

your nit-pick is wrong

Originally posted by Snowy_River
Just to be nit-picky, that should be '4TeB', or '4TB', as it's four tera-bytes.

No, 4 TB is 4,000,000,000,000 bytes, or 10^12.

4 TiB is 2^42, or 4,398,046,511,104 bytes.


To wit:

http://physics.nist.gov/cuu/Units/binary.html

http://www.theregister.co.uk/content/54/22734.html

 

[mathiasr]

Re: your nit-pick is wrong

Originally posted by AidenShaw
4 TiB is 2^42, or 4,398,046,511,104 bytes.

4 tebibytes TiB
4,096 gibibytes GiB
4,194,304 mebibytes MiB
4,294,967,296 kibibytes KiB

4.4 TB
4,398 GB
4,398,046 MB
4,398,046,511 kB
43,980,465,111 hB
439,804,651,110 daB
4,398,046,511,104 B
43,980,465,111,040 dB Huuuuh, this is loud!

 

[Genie]

I can't wait for a 970 mac.

Should I buy one right away or wait for the 2nd revision?
How much faster do you think it'll be than my dual 1G?
I just put an acard raid in and that sped Photoshop up some but I need more speed!

 

[ColoJohnBoy]

As nice as it would be, and I am holding out hope, I sincerely doubt that the PPC 970's will be used until sometime this fall, and about a year later they'll be relegated to basic consumer level with the onslaught of the Power5 chip. But, hey, here's to hoping. I'd love the following:

15.4" Aluminum PowerBook, 1" Thick
Slot-Load DVD-R/CD-RW Drive, with 2x DVD capability
1.4 GHz PPC 970 Processor
2 GB PC3700 DDR-RAM
100 GB Hard Drive
ATI Mobility Radeon 128 MB Video Card (If there is one)
Built-in Bluetooth
AirPort Extreme
Light-up Keyboard
FireWire 400 & 800
5.3 Lbs.

Visit Blue Pudding!
http://bluepudding.1hwy.com

 

[Snowy_River]

Re: your nit-pick is wrong

Originally posted by AidenShaw
No, 4 TB is 4,000,000,000,000 bytes, or 10^12.

4 TiB is 2^42, or 4,398,046,511,104 bytes.


To wit:

http://physics.nist.gov/cuu/Units/binary.html

http://www.theregister.co.uk/content/54/22734.html

Gads, this is awkward. Tebi-bytes? Uck. I understand where how they derived it, but still... Kibi-bytes is even worse.

In my defense, while this seems to be a five year old "standard", I can honestly say that I have never heard of it before now, despite being fairly in touch with tech matters. Everyone I've ever talked to have used the SI units with the full knowledge that in binary references it is used in powers of 2^10, not 10^3. (Though I was aware that disk manufacturers used decimal when reporting disk size...)


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