Author Topic: Question for all you x86 experts  (Read 5242 times)

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Offline .: Mac :.

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Question for all you x86 experts
« on: April 26, 2006, 03:26:39 AM »
All my life I have uses PowerPC based Computers. Now that the PowerPC is gone away I have some questions for you guys.

For all questions I would like an awnser for BOTH AMD and intel unless i say otherwise

1) what is the x86 equal to Altivec (SIMD instructions) (answered)

2) How many General Purpose Registers are there for an x86 chip, the Power PC had 32(answered)

3) do x86 chips use SOI technology to reduce Power leakage?

4) Does AMD have a equal to the PowerPC Dynamic Speed Controller (intel Speedstep)

5) What type of ZIF sockets are currently in use for x86 chips

6) How many Pipeline Stages are in the x86 chips (powerPC chips had only 7 hence their lower clock speed)
« Last Edit: April 26, 2006, 12:29:08 PM by .: Mac :. »
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Offline igor

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Re: Question for all you x86 experts
« Reply #1 on: April 26, 2006, 10:12:05 AM »
Well, you may want to download some documents from Intel to get precise answers ;)

1) what is the x86 equal to Altivec (SIMD instructions)

SIMD instructions :)  Could be MMX, SSE (SSE2, SSE3), ...

2) How many General Purpose Registers are there for an x86 chip, the Power PC had 32

Only 8 - and some of them (like the stack pointer) is rather hard to use as a "general purpose register", even though some people really use them as such :)

6) How many Pipeline Stages are in the x86 chips (powerPC chips had only 7 hence their lower clock speed)

Don't know (havily depends on the particular model) - but what do you want to conclude from that information? You can't say that "the more, the better", or even opposite.

Offline .: Mac :.

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Re: Question for all you x86 experts
« Reply #2 on: April 26, 2006, 12:26:23 PM »
igor, the reason I want to know about pipeline stages is years ago when the Pentium 4 reached 1.8Ghz and the PowerPC G4 was at 867Mhz Apple explained something called the Megahertz Myth.  processor with a higer clock speed may not be any faster than another processor with a lower clockspeed.

they argued that (at that time)
PowerPC 7450 (G4) - 7 stage
Pentium 4 - 20 stage

that the long pipeline allowed intel to get the high clock speed but that the G4 could still keep up. I think this is why some AMD chips perform better than intel although they  have a lower clockspeed

so ever since that day i do not judge perormance soley on Clockspeed but how many stages they use to reach that speed

Not only apple believes in the megahertz myth AMD does too: http://www.amd.com/us-en/Processors/SellAMDProducts/0,,30_177_3532_3839%5E4578,00.html
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Offline igor

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Re: Question for all you x86 experts
« Reply #3 on: April 26, 2006, 12:35:37 PM »
Of course I agree that the frequency alone doesn't make the performance, I just don't think that you can conclude much from the pipeline length.
Longer pipeline makes it possible to split the execution of an instruction into more parts, thus executing more instructions in parallel. So, you also can't say "the shorter the pipeline, the better"; there are many other factors in the CPU design that affect the performance.

Offline RejZoR

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Re: Question for all you x86 experts
« Reply #4 on: April 26, 2006, 01:28:55 PM »
3) do x86 chips use SOI technology to reduce Power leakage?
SOI or Silicon On Insulator is a fab tech that reduces cost and heat generation. So yes, thats true. If i remember AMD was the first to use such tech for their CPUs.

4) Does AMD have a equal to the PowerPC Dynamic Speed Controller (intel Speedstep)
Yes, they have. It's called Cool'n'Quiet (implimented in all AMD64 chips) and AMD PowerNow! implimented in AMD mobile CPUs.

5) What type of ZIF sockets are currently in use for x86 chips
There are various sockets for various CPU models. I'm not exactly into Intel CPUs and their sockets but AMD is using Socket A (Athlon4,AthlonXP), Socket 754 (Athlon 64), Socket 939 (Athlon 64), Socket 940 (Opteron), Socket AM2 (this is the latest one which is not yet available to buy).

It's also known that Pentium 4 are using ridiculously long pipelines in order to achieve higher frequencies. Thats why first P4's sucked big time compared to ultra fast Athlons in those days.
« Last Edit: April 26, 2006, 01:31:26 PM by RejZoR »
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Offline xistenz

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Re: Question for all you x86 experts
« Reply #5 on: April 26, 2006, 04:08:46 PM »
5) What type of ZIF sockets are currently in use for x86 chips

RejZoR has answered the AMD side. Here is the Intel side...

Currently Intel uses a socket 775 for all their processors. Unlike every other socket, the 775 uses a LGA (Land Grid Array) as opposed to a PGA (Pin Grid Array). What this means is that the pins are not on the processor, but on the motherboard.

The older P4 socket is the 478 which is a PGA.

Offline .: Mac :.

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Re: Question for all you x86 experts
« Reply #6 on: April 26, 2006, 06:33:12 PM »
I know all about LGA, PowerPC Processors use them, thanks rejzor for the info on AMD.

Igor, i can see why Alwil holds on to you :)

when I have a question I usually just email one of my pals in San Fran, CA where the Apple Hardware engineers are located, but with most of them still assigned to the PowerPC development team they have not had the time to re aquaint themselves with the x86 architecture.

I get some very Tech Savy customers in the store from time to time so its important i keep up to tate with the current technology trends
« Last Edit: April 26, 2006, 06:35:30 PM by .: Mac :. »
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Offline Vlk

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Re: Question for all you x86 experts
« Reply #7 on: April 26, 2006, 06:39:39 PM »
.: Mac :., just out of my curiosity would you be interested in beta testing avast for Mac?
It's a universal binary so it should work on Gx as well as Intel.

Thx.
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Offline .: Mac :.

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Re: Question for all you x86 experts
« Reply #8 on: April 26, 2006, 06:46:10 PM »
Actually I would love to test the avast for mac. and im glad it is a Universal binary from the start.

I know you guys were hiding that mac version ;)

just use the email link in my profile to contact me

I own PowerPC Based macs not intel ones although i can access them at work
« Last Edit: April 26, 2006, 06:56:22 PM by .: Mac :. »
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Offline Vlk

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Re: Question for all you x86 experts
« Reply #9 on: April 26, 2006, 07:05:29 PM »
An early beta should be ready early next week. Thanks a lot :)
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Offline .: Mac :.

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Re: Question for all you x86 experts
« Reply #10 on: April 27, 2006, 03:51:41 AM »
Vlk, you guys will make an effort to add the Mac OS X viruses to the database i hope as it is a very likely event that their will continue to be viruses released for OS X in the future and not just the proof of concept ones  now that are not ITW
"People who are really serious about software should make their own hardware." - Alan Kay