Mask Revision 1 Of The 68060 Processor Series Question

[CU_AMiGA]

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,

[Framiga]

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.

[bloodline]

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.

[CU_AMiGA]

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?

[Framiga]

CU_AMIGA . . . define "problems" :-)

[CU_AMiGA]

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,

[Piru]

@CU_AMIGA

What problems will i get though (if any)?

I suggest you read the NoBypass.text in 68060fix.lha.

[darkcoder]

@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.

[CU_AMiGA]

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,

[Framiga]

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

[CU_AMiGA]

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.

[Piru]

@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.

[delshay]

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..