Amiga.org
Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: CU_AMiGA on February 22, 2005, 03:17:16 PM
-
Hey Yo!
The Blizzard 1260 i own was made in 1994/95 and has the revision 1 68060. I have heard that the revision 1 of the 68060 has problems (bugs) with the Store/Load Bypass option, so i have disabled this option on my startup sequence. The question i have is that would this affect my system in anyway (any slowdown?) and would it be possible to put a higher revision 68060 instead of the one i have got already.
Regards,
-
do you have like this?
10.AmigaOS:> cpu060
System: 68060MC Mask 0-1f43G,2f43G-0g65V Revision 1
Settings:
(INST: Cache Burst)
(DATA: Cache Burst)
(BRANCH: Cache)
(Superscalar)
(WriteBuffer)
(Store/Load Bypass)
Register:
CACR=$A0808000
PCR=$04300101
BUSCR=$00000000
no problems . . . OC at 60 Mhz with only a heatsink.
BTW . . .the cpu is labeled as XC . . . and at 50 Mhz it stays cool.
-
CU_AMiGA wrote:
Hey Yo!
The Blizzard 1260 i own was made in 1994/95 and has the revision 1 68060. I have heard that the revision 1 of the 68060 has problems (bugs) with the Store/Load Bypass option, so i have disabled this option on my startup sequence. The question i have is that would this affect my system in anyway (any slowdown?) and would it be possible to put a higher revision 68060 instead of the one i have got already.
Regards,
From the Mot website, it seems switching the "bypass Load/Store" on, disables one of the pipes, effectivly causing your CPU to run at 3/4 it's maximum performace. Though I only scanned the doc I could have misunderstood what it was saying.
So don't bypass the Load/Store unless you have problems.
-
Hey Yo!
Here is what i have:
14.RAM:> cpu060
System: 68060MC Mask 0-1f43G,2f43G-0g65V Revision 1
Settings:
(INST: Cache Burst)
(DATA: Cache Burst)
(BRANCH: Cache)
(Superscalar)
(WriteBuffer)
(Store/Load Bypass disabled)
I will enable it again until i get problems. What problems will i get though (if any)?
Regards,
-EDIT-
I am not really up for overclocking, as i am using desktop now :-) Would it be possible to swap 68060?
-
CU_AMIGA . . . define "problems" :-)
-
Framiga wrote:
CU_AMIGA . . . define "problems" :-)
I dunno, any "problems": Crashing, freezing, Programs not working, scrambled screen, anything. If Amiga hisses or growls at me, that is also a "problem" :-)
Regards,
-
@CU_AMIGA
What problems will i get though (if any)?
I suggest you read the NoBypass.text in 68060fix.lha (http://www.aminet.net/util/boot/68060fix.lha).
-
@bloodline
I don't think it's so big deal...
from the 68060 errata rev. 4.0:
"The store/load bypass feature, which eliminates a pipeline stall in scenarios of successive instructions storing and loding back data from the same adress, should have very limited performance impact on most programs"
store/load is an optimization made by the pipeline: when you disable it you just add a (some ?) stall (i.e., wait cycle) in the sequence instruction that could be optimized.
My 060 too has this problem, but I don't mind replacing it.
-
Hey Yo!
I don't want to sound like a complete idiot here, but i forgotten how to enable the Store/Load Bypass thing. Ocording to my notes, i used a "cpu060 nstb" command in my startup sequence. But i couldn't find it. How do i enable this bugger then.
Oh, and i will look at that 68060fix document as well, thanks.
Regards,
-
Hi CU_AMIGA
so you have the Store/Load bypass DISABLED without any command? (cpu060 ...)
Anyway try to launch the NoBypass prog (in 68060fix.lha).
It switches from Enabled to Disabled or viceversa.
Bye
-
Hey Yo!
After much deciding, i think i will leave the store/load bypass thingy disabled. I got a little fright when bloodyhound said it would affect a 1/4 of my Amiga speed performance.
-
@CU_AMiGA
I got a little fright when bloodyhound said it would affect a 1/4 of my Amiga speed performance.
It does not affect 1/4 of your Amiga speed. It affects 1/4 for one specific operation, not general amiga performance.
You will have hard time noticing any performance difference.
-
is there any point in overclocking the BLIZZPPC 68k?..
**if & **when** a ppc O/S is avalible to BLIZZPPC onwers, the BVISION bus will run at full speed..
correct me if im wrong..
as i was going to try & get hold of a MC68060RC60 to inprove BVISION bus speed..