Welcome to the MacNN Forums.

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

You are here: MacNN Forums > Enthusiast Zone > Classic Macs and Mac OS > Pentium 4 and Cache

Pentium 4 and Cache
Thread Tools
embermage13
Guest
Status:
Reply With Quote
Dec 9, 2000, 01:06 PM
 
I was at Intel's site loking at P4 info, and it said it only had 256k cache. Well, doesn't the G3 have 512k (except the iBook which I think has 256), and the G4 1MB? If so, then am I missing something? Are the two cache's different types?

Thanks,
Kyle
     
Jsnuff1
Mac Elite
Join Date: Jun 2000
Location: NY
Status: Offline
Reply With Quote
Dec 9, 2000, 01:28 PM
 
yea the 256k is level 1 cache which is on the proccessor, the g4 has 1mb L2 backside cache which is not on the processor, the diffence between L1 and L2 is that the processor can communicate faster whith the cache memory when its on the chip itself, the draw back though is that you cant put as much on the chip as you can when its not on the chip like the g4
     
Cipher13
Registered User
Join Date: Apr 2000
Status: Offline
Reply With Quote
Dec 9, 2000, 10:03 PM
 
1 meg of backside L2 is better than 256K of on-die - the new G3's have 256K on-die...

Cipher13
     
t_hah
Mac Elite
Join Date: Dec 2000
Location: Tempe, AZ
Status: Offline
Reply With Quote
Dec 10, 2000, 05:00 PM
 
This all depends on which G3 we are talking about. Some G3's have 1MB L1 cache...otherwise everything seems to be correct.
     
acedloring
Guest
Status:
Reply With Quote
Dec 13, 2000, 02:44 PM
 
The Powerbooks, even the new Firewires, use a 1mg L2 cache running at 5:2. The G3 towers, G4s and Cube also use either a 512 or 1mg L2 cache. The only processor that doesn't use this are the newest ibooks which use an entirely new G3 chip called the 750cx instead of the 750 which is used in all the other models. The 750cx, from what I understand, uses an on-die 256k L2 cache instead. Because this cache runs at full processor speed, it is said to be faster than a 512k L2 cache running at half the processor speed. However, the on-die 256k L2 cache is still significantly slower than the 1mg L2 cache presently in the Firewire Powerbooks. I think the new ibooks use this on-die cache because it consumes less power and really helps in increasing battery time. Anyway, hope this helps...
     
olePigeon
Clinically Insane
Join Date: Dec 1999
Status: Offline
Reply With Quote
Dec 17, 2000, 11:29 PM
 

Actually, the Pentium IV has a 256 L2 "transfer" cache. Whatever the hell that is. I'm assuming it's on chip. It's similar to the G3 750cx.

The G5 will sport 128K L1 on chip Cache, 512k L2 on chip cache, and 1MB L3 backside cache. Not only that, but IBM has a new chip they've just announced finishing the core. It leaves plenty of room for growth up to 10GHz. I has the cache mentioned above and is processed at .13u microns. (Petnium 4 is at .18u.)
www.chips.ibm.com
"…I contend that we are both atheists. I just believe in one fewer god than
you do. When you understand why you dismiss all the other possible gods,
you will understand why I dismiss yours." - Stephen F. Roberts
     
Jsnuff1
Mac Elite
Join Date: Jun 2000
Location: NY
Status: Offline
Reply With Quote
Dec 18, 2000, 12:48 AM
 
yea and when will we be seeing these chips...hmmm 10 years from now if were lucky
     
Cipher13
Registered User
Join Date: Apr 2000
Status: Offline
Reply With Quote
Dec 18, 2000, 07:11 AM
 
Originally posted by t_hah:
This all depends on which G3 we are talking about. Some G3's have 1MB L1 cache...otherwise everything seems to be correct.
There is no G3 with 1 meg L1 cache. There are G3's with 1 meg L2 cache.

Cipher13
     
Gregory
Grizzled Veteran
Join Date: Sep 1999
Status: Offline
Reply With Quote
Dec 19, 2000, 09:01 AM
 
The on-die runs at same speed 1:1 as cpu so you are looking at 500 mhz L2. And most will also have an L3 cache. Small, slow - in some cases non-existent L2 caches were the worst performing machines ever created.

I'd suggest doing some reading over on ChipGeek and Tom's Hardware along with front side bus, DDR, and get an understanding of what 2001 will likely offer.

Changes in the Pentium4 means that operations that once relied on FPU now use a newer processing unit - forcing rewriting of software that relied on fpu as well as new benchmarking.

Now if AMD and MOTO would get together and get some decent yields at higher clocks...
     
petek
Forum Regular
Join Date: Feb 2000
Location: Upper Black Eddy, PA
Status: Offline
Reply With Quote
Dec 19, 2000, 01:09 PM
 
This G3/400/512K has 64K L1 (on die) & 512K L2 (backside). (Sonnet Crescendo PCI card)
     
   
 
Forum Links
Forum Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Top
Privacy Policy
All times are GMT -4. The time now is 03:13 PM.
All contents of these forums © 1995-2017 MacNN. All rights reserved.
Branding + Design: www.gesamtbild.com
vBulletin v.3.8.8 © 2000-2017, Jelsoft Enterprises Ltd.,