Speculative Processing |
November, 07, 2002 5:26 PM |
avit |
I have found that my Jaguar system is much more stable with Speculative Processing enabled! After going through the thread of 99 speculations (no pun) about what could be causing Jaguar to crash so often, I guess I must have enabled it at some point and things were running well for a while. I still had a few odd WindowServer crashes and a couple kernel panics, but no "hard" freezes like before. I had disabled Spec Processing with the PowerLogix NVRAM floppy in order to boot from a Norton CD to scan my HD for something that fsck couldn't fix. Suddenly things were crashing a lot again, and I didn't clue into it at first. Those of you who are reporting that your system is more stable with Sonnet's or Ryan's cache enabler, this could be why. As far as I know, the PowerLogix control panel is the only one which gives access to turn off Spec Processing. Honestly, I haven't tried the others, so correct me if I'm wrong. And if your system is crashing lots, try this. It's still not a perfect solution, but this could be part of it. |
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RE: Booting for Norton |
November, 18, 2002 7:09 PM |
avit |
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I booted from a OS9 Norton CD. That's why I had to disable Spec Proc in the first place: OS9 doesn't boot with it. The Powerlogix floppy is supplied for when your Mac has the "flashing floppy icon" and doesn't find a drive to boot from. The floppy sets NVRAM to disable spec proc, then OS9 can boot. OSX seems to prefer spec proc, so leave it on. |
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RE: Speculative Processing |
November, 10, 2002 8:42 PM |
OSXGuru |
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Just to add a few more details: The NVRAM patch which XPostFacto installs will turn off speculative processing. The theory is that this may be required at the Open Firmware stage of the boot process--I'm not sure whether that is true or not, but it seems prudent. Then the custom version of BootX installed by XPostFacto will turn it back on, just before calling the kernel. (And just to make sure, the ApplePowerSurgePE.kext will also turn it on). Then L2CacheConfig just leaves it alone. |
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RE: Speculative Processing |
November, 10, 2002 8:39 PM |
OSXGuru |
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There isn't a "Speculative Processing" setting in L2CacheConfig anymore because L2CacheConfig just leaves speculative processing alone now. Since it's on by default, that would leave it on, unless something else turns it off. |
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RE: Speculative Processing |
November, 09, 2002 6:05 PM |
paul_findley |
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Avit: How did you boot from a Norton OSX CD on an old world machine? |
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RE: Speculative Processing |
November, 08, 2002 11:06 AM |
avit |
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I have PLX CacheControl 2.1b4 and it's definitely there. I have a Powerforce G4/450, so it might not be available, depending on your CPU? Do the 7540 "G4e" (or whatever the fast ones are called) have Spec Processing always-on? |
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RE: Speculative Processing |
November, 08, 2002 9:40 AM |
marcush |
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I was referring to Cache Control X v2.1b4 and the previous version 2.1b1. I have not used L2CacheConfig in a while so it might have been removed but I don't see why. If you have a Sonnet G4 800 I'm sure that is why you don't see speculative access in Cache Control X. It disappeared when I upgraded from an XLR G4/450. I'm guessing it the same case with L2CacheConfig. |
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RE: Speculative Processing |
November, 08, 2002 7:17 AM |
drc |
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What version of Cache Control are we talking about here? With Cache Control X 2.1b4 I can't find any reference to speculative processing. Can't find it with L2CacheConfig either. |
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RE: Speculative Processing |
November, 07, 2002 10:49 PM |
marcush |
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I remember reading a comment by Ryan last year when XpostFacto was Unsupported Utility X that OSX does all of the necessary things to allow speculative access on oldworld Macs. I don't think he elaborated on that but I took him at his word and enabled speculative access with L2CacheConfig. When I started using Cache Control X I continued to leave it enabled. I never had a problem that I could trace to speculative access so I was happy to be able to make use of it. I did notice, however, and was somewhat dissapointed to find that when I upgraded to the Sonnet G4 800 that the tab containing the speculative access setting disappeared from Cache Control X. I'm not at all sure what that means but never saw any comment mentioning it. I wonder if this is what other people saw also? |