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Topic |
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TiMacLover
Senior Member
USA
1282 Posts |
 Posted - 26 Jan 2002 : 19:04:03
ok I got a question, what if I had like a a 7200/90Mhz and I had a 7600/100Mhz and each had a G3/400Mhz, would they be the same speed even tho the 7200 was originally slower? Same thing with upgrading to PPC in 68k?jeremy "I keep my friends close, but I keep my enemies closer"
Napoleon My AOL, AIM Sceen name is got 007s milk Covert Ops
N.F.C Newton Force Captain
68k Macintosh Liberation Army
Macs Liberated:15 |
FireWire is fast
General, 4 star
USA
1559 Posts |
Posted - 26 Jan 2002 : 22:02:48
The bottleneck between the processor and everything is the system bus. The faster the system bus, the smaller the bottleneck, therefore giving you faster performance.I'm not quite sure about the 7600's and the 7200's system bus. (perhaps 50 MHz and 40 MHz, respectively?). So lets say the 7200 has a 40 MHz bus and the 7600 has a 50 MHz bus. The 400 MHz G3 upgrade would be faster in the 7600. Dig? (this should be in Balloon Help, by the way) --------------------
FireWire is fast
General, 4 star
beholder of the Quadra/Centris Stick of Justice™ Edited by - FireWire is fast on 26 Jan 2002 22:03:27 |
Trash80toG-4
NIGHT STALKER
USA
2899 Posts |
Posted - 26 Jan 2002 : 22:19:44
quote:
ok I got a question, what if I had like a a 7200/90Mhz and I had a 7600/100Mhz and each had a G3/400Mhz, would they be the same speed even tho the 7200 was originally slower? Same thing with upgrading to PPC in 68k?
As a general rule for comparing systems of differing ages utilizing exactly the same cpu:
If the yyyy's system bus is a little faster, or the video subsystem is a little better, or the disk i/o is a little faster, it will perform better with the same accelerator than would an earlier xxxx system and neither would probably be able to keep up with a newer zzzz designed at the time of the release of the cpu on the accelerator, because of general advances in architecture, mobo components, etc.jt
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danamania
Official 68k Muse
Australia
1193 Posts |
Posted - 26 Jan 2002 : 23:57:59
quote:
ok I got a question, what if I had like a a 7200/90Mhz and I had a 7600/100Mhz and each had a G3/400Mhz, would they be the same speed even tho the 7200 was originally slower? Same thing with upgrading to PPC in 68k?
One thing a few others have mentioned is Bus speed - which is a biggie - however that's not always directly proportional to the cpu speed or type - especially in the 2 machines you picked (almost). a 7200/90 has a system bus of 45Mhz, and the CPU runs twice that. a 7600/120 has a system bus of -40-Mhz, and the CPU runs 3 times that. If an accelerator went just on bus speed, it may go say, 8x speed - which would make the 7200/90 run at 8x45 = 360Mhz, and the 7600/120 run at 8x40 = 320Mhz. It can get more complex too! What if the accelerator could not physically run faster than 350Mhz because of the components it uses? that would mean the 7200 may only be able to run at 7x45 = 315Mhz, while the 7600 could stay at 320. One of Sonnet's 8100 Nubus G3 accelerators has just those issues - an 8100/80 can be run at nearly full speed, while the faster bus speed of one of the later models would go above the capabilities of the G3 chip they use - so it has to use a lower bus multiplier. it's not a big drama really, compared to the difference between an 8100/80 or 8100/110 machine in the first place... it doesn't much matter whether the accelerator gives you a 495Mhz or a 480Mhz G3... it'll still be an awesome jump! The best option is to check out how each accelerator works in the machines themselves, sonnet is one company that has most of the info on their site... be well!
dana
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TiMacLover
Senior Member
USA
1282 Posts |
Posted - 27 Jan 2002 : 05:22:46
A lot of information to take in but I think I got it, the faster the bus speed the better performance with the upgrade? Thanksjeremy "I keep my friends close, but I keep my enemies closer"
Napoleon My AOL, AIM Sceen name is got 007s milk Covert Ops
N.F.C Newton Force Captain
68k Macintosh Liberation Army
Macs Liberated:15 |
~Coxy
Leader, Tactical Ops Unit
Australia
2822 Posts |
Posted - 27 Jan 2002 : 10:30:42
Not always. Check it with your praticular models, is what she said.~Coxy - Leader, Tactical Operations Unit
68k Macintosh Liberation Army (now with forums!)
00013 Macs liberated. |
Trash80toG-4
NIGHT STALKER
USA
2899 Posts |
Posted - 27 Jan 2002 : 10:42:19
quote:
Not always. Check it with your praticular models, is what she said.
Yup, I tried to imply the same thing, but I'm only occasionally coherent.
jt
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Mhz Matter in Upgrades?
68k of the Week: kastegir's PowerBook 180.