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haemogoblin

B&W upgrade 1Ghz G4?

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Especially when it is often cheaper to buy a Quicksilver for less than that of the Sonnet Encore 1Ghz.

 

I have had a Sonnet Encore 1Ghz in my B&W G4 and it was nice and fast, until I broke (and then lost) the special ATX cable. I played Deus Ex on it. What annoyed me most about it is the reboot that is required. Boot time is much longer. It also cut out on me every now and then but I reckoned that one of 4 sticks of RAM was bad. As I hinted above, if I were doing it again, I'd get a Quicksilver. Mac OS 8.6 is nice but Mac OS 9.0.x is also good.

Edited by ArmorAlley

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Thanks for the info, I was hoping someone who had owned one might chime in and give some first hand experience. So would you say, that upgrading from say a G4 500mhz to the 1Ghz wont actually be that much of an upgrade? That the cut you take to the system bus is more detrimental to overall perfomance? At the moment my system does take a while to boot, say compared to my G4 1.55Ghz powerbook, but thats to expected. I don't think I could handle it being slower, thats the opposite of what I was hoping to achieve.

 

I'd prefer not to buy another system but max out the B/W as best I can. I've just upgraded the video card to a Radeon 7000, in place of the stock Rage 128. Thats made a huge difference to gaming, but I was hoping I might be able to upgrade the CPU. I think the B/W will go up to 700mhz G4, before the bus speed has to be dropped to 66mhz. Where as no such drop exists with the G3, sadly however G3 upgrades are really rare on the ground.

 

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The PowerPC 7410 can apparently be had in 600-700MHz varieties, and it's these that you'll need to use if you want a B&W G3 or Yikes! G4 on a full 100MHz memory bus. 

 

For some reason the later models with PowerPC 745x variants use FPGAs to interface to the memory bus, and these FPGAs can't operate faster than 66MHz, thus the requirement to drop your bus speed. Oddly, the same 800-1000MHz 745x chips don't appear to require FPGAs in the older beige Macs.

 

The difference between the 7410 and the 745x chips is the use of full-speed L2 cache and the inclusion of L3 caches on the 745x where the 7410 has only half-speed (at most) L2 cache. You'll still get a good performance boost out of the 745x-based upgrades even with the memory bus speed drop.

 

The best 100MHz bus-based chips for these are the 750GX, which has 1MB of full-speed L2 cache in addition to core speeds up to 1.2GHz. These are oddly hard to find though, even though they should have been less expensive than equivalent G4 upgrades. Possibly because, without AltiVec, they struggle with some of the pretty stuff under 10.4 Tiger and can't be used at all with 10.5 Leopard.

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Well by a weird series of events that began with looking at Radeon cards, I appear to now have a Sonnet G4 1Ghz on it's way to me. So that is going to be interesting.

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On 7/10/2020 at 5:35 AM, Franklinstein said:

For some reason the later models with PowerPC 745x variants use FPGAs to interface to the memory bus, and these FPGAs can't operate faster than 66MHz, thus the requirement to drop your bus speed. Oddly, the same 800-1000MHz 745x chips don't appear to require FPGAs in the older beige Macs.

I believe this is a home-made issue by Sonnet.

Notice how you can install the same upgrade card in two different orientations in either the B/W or Beige G3s?

If they would have opted to do a different board layout for each machine they wouldn’t have needed the FPGA setup to shift the signal lines around to match the orientation in the ZIF socket.

The 745x runs just fine with any slower or faster bus speed you throw at it in other machines like you already noticed.

Edited by Bolle

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On 7/13/2020 at 6:25 AM, Bolle said:

Notice how you can install the same upgrade card in two different orientations in either the B/W or Beige G3s?

Is that so? That never occurred to me before, probably because I never tried to do a side-by-side install or transplant from beige to B&W. That use case makes sense though. Very interesting bit of engineering.

 

Did anybody build 745x-based upgrades exclusively for the B&W G3/Yikes! G4 that didn't include the FPGA adaptation? I don't think I've ever seen any.

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