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Just bought a 2008 Mac Pro
- Thread starter tpivette89
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With many or most Intel processors, the newer models with EO stepping often overclock somewhat better than the older models with CO stepping. Stepping is basically the CPU's version number. Whenever Intel improves the manufacturing process, they make a new stepping. Steppings are typically two characters long (like C0, C1, or E0). It's also sometimes called the revision.
EO Stepping is a good thing...
EO Stepping is a good thing...
better steppings are generally a good thing
up until the point your Computer lacks Microcode for said stepping because said stepping uses a new CPUID and said computer will refuse to post with unknown CPUIDs
(at least this is what I understand the case to be on the Mac Pro 3,1. of course if I ever get a 3,1 ill buy some cheap E0 CPUs and test it for sure)I actually have a cheapo Gigabyte 945GZM-S2 Rev 3.9 i945 LGA 775 Motherboard kicking around that barely supports first gen C2Ds but I managed to get it running one of the last C2D models (pulled from a dead iMac) quite nicely by adding the microcode for it to the BIOS of the mobo (before while it would POST it was missing a bunch of its instruction sets thanks to no microcode, tbh I was surprised it POSTed in the first place LOL) only thing that does not work still is SpeedStepping but ThrottleStop solves that issue
http://valid.x86.fr/56lzvi
its a shame no one has figured out how to hack up the EFI in Macs, because then we could try and manually add the microcode to say a 3,1s firmware, flash it then try some E0 CPUs and possibly get the X5492 working for example.
"Computer lacks Microcode for said stepping" aw now that makes sense ! But the thing is the Xeon X5470 has only ever had EO stepping and a CPUID = 1067Ah
And just because one CPU with "EO" stepping won't boot doesn't mean a X5470 with EO stepping won't work...
And just because one CPU with "EO" stepping won't boot doesn't mean a X5470 with EO stepping won't work...
when an entire stepping does not work in a Machine it means any CPU that uses that stepping will fail to work sadly.
I will say I did a bit of internet sleuthing and while I cant find any one who fitted a E0 stepping CPU into a Mac Pro 3,1 and I saw plenty of people saying it wont work when people asked about it.
I cant seem to find the original source of this info? (ie who was it that tried E0 CPUs only for them not to work? I just checked the service guide and it does not mention anything there)
I had also read about the incompatibility of the E0 stepping... if this was not the case, I would've tried the X5270s instead of the X5272s. The only factor that would've kept me from installing these, is the 1333 FSB vs the X5272s 1600. Would this have any ill effect on performance?
Of course the X5492s are the best of both worlds... 1600 FSB and 3.4ghz quad cores. If these CPUs did work, that would be an awesome upgrade for the 3,1. If they weren't so pricey ($85+ each on eBay), I would probably try them.
Of course the X5492s are the best of both worlds... 1600 FSB and 3.4ghz quad cores. If these CPUs did work, that would be an awesome upgrade for the 3,1. If they weren't so pricey ($85+ each on eBay), I would probably try them.
But stepping is nothing more than updates to the CPU's with an update to "EO" stepping on one CPU being nothing like an update to "EO" stepping on an another, "EO" is nothing more than a name given to a change on a CPU BUT if others have said "EO's" won't work I'm not going to try and say they will...
what i dont think you realise is All the Penryn CPUs (apart from Like Dunnington LOL) share the same dies/silicon a Harpertown CPU is just 2 Penryn dies on an LGA771 package.
and that the difference between say an E0 Stepping Xeon X5492 and an E0 X5470 (ignoring specs like TDP etc) is just whatever multiplier and name intel gave those CPUs from the factory, if you look at them under a microscope they will be identical for the most part.
if the Silicon was any different then the CPUID would be different just like a C0 vs E0 stepping CPU...
I disagree, Steppings are iterative improvements. The letter usually indicates major revisions while the number indicates minor revisions. E1 would indicate the 1st minor revision of the 4th major revision of a given design.
Major revisions are either due to significant bug fix(es), performance improvements, re-organization of the silicon floorplan, etc. Minor revisions can be for just about any reason including minor tweaks and fixes and even though all the Penryn CPUs (apart from Like Dunnington LOL) share the same dies/silicon, Different CPU's get different revisions as they make improvements on the different CPU's for whatever reason.
Or to put it a different way, Stepping level refers to the introduction or revision of the lithographic photomask or masks within the set of plates that generate the pattern that produces an integrated circuit. The term originated from the name of the equipment ("steppers") that exposes the photoresist to light, Integrated circuits have two primary classes of mask sets, base layers that are used to build the structures that make up the logic such as transistors, and metal layers that connect the logic together.
Typically, when an integrated circuit manufacturer such as Intel or AMD invests money to do a stepping (i.e. a revision to the masks), they have found bugs in the logic, have made improvements to the design that allow for faster processing, have found a way to increase yield or improve the "bin splits" (i.e., create faster transistors and hence faster CPUs), improve maneuverability to more easily identify marginal circuits, or reduce test time which can reduce the cost of testing the part.
Many integrated circuits have a means of interrogating them in order to discover their stepping level. For example, on x86 CPUs executing the CPUID with the EAX register set to '1' will place values in other registers that show the CPU's stepping level.
Stepping identifiers are commonly an alphabetic letter followed by a numeric number, for example, "B2." Usually, the letter indicates the revision level of a chip's base layers and the number indicates the revision level of the metal layers. A change in the letter indicates a change to the base layer mask revision and metal layers, while a change in the number indicates a metal-layer–only mask revision. An analogy is the major/minor revision numbers used in software versioning. Base layer revision changes are time-consuming and more expensive for the manufacturer, but some fixes are difficult or impossible to accomplish with metal-only changes to the integrated circuit.
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you literally took that entire post right from wikipedia...
https://en.wikipedia.org/wiki/Stepping_level
in this post you say ""EO" stepping on one CPU being nothing like an update to "EO" stepping on an another" when you have 2 CPUs in the same line up on the same uArch the updates are going to be the same. 2 Harpertown CPUs are going to be the same thing apart from how intel marks them up so to speak (I recommend looking up binning). (an X5482 and E5462 of the same stepping will look the same under the microscope)
of course for example an E0 Stepping Pentium 4 is going to be diffrent from an E0 stepping Penryn CPU. (because they are steppings of completely diffrent uArches, but im solely talking about 1 uArch here)
anyways we are just going round in circles here :/
"entire post right from wikipedia"
Nope, Only the second half.....
But anyways, Agree to disagree...
Nope, Only the second half.....
But anyways, Agree to disagree...
...Disagree on what? I thought the Intel manufacturing process was a matter of fact, not a matter of opinion, so I am legitimately confused on what you want to disagree on? Unless I'm reading that wrong?
I disagree that an "EO" stepping update on the X5482 will be exactly the same as an "EO" stepping update on the E5462 just because they share the same dies/silicon (uArch), I believe that steppings are iterative improvements, re-organization of the silicon floorplan, etc. Minor revisions can be for just about any reason including minor tweaks and fixes and even though all the uArch CPUs share the same dies/silicon, Different CPU's get different revisions as they make improvements on the different CPU's for whatever reason.