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Paint Yourself An Athlon MP
SNIa asks: "How many people are checking the prices of AMD chips after seeing this?" and points out this article at HardwareZone.com about modifying Athlon XP processors to perform like MPs. No guarantees, except a voided warranty.
. However, do note that connecting these pads together does not automatically modify the CPU into an Athlon MP. It stays as an Athlon XP.
It doesn't change the performance of the chip, only allows you to run two of the newer XPs in a dual motherboard.
I've had enough abrasive sigs. Kittens are cute and fuzzy.
I have worked in AMD's R&D department for the last six years. I was pretty involved in development of the XP and MP series in particular. Let me make clear that modding XP chips to work as MPs is a bad idea and will most likely result in one or two cooked CPUs within a month.
Yes, we know about the trace. We put it there to differentiate between the XP chips which contained our hacks to make it play nice in multiprocessing systems (aka the Athlon MP), and the chips not containing those hacks (aka the Athlon XP). Think of it like this: converting your car to diesel would give a great increase in fuel mileage, but it cannot be achieved by simply adding a "DIESEL FUEL ONLY" decal by the gas tank.
I don't want to sound elitist and say "Leave the chip-mods to the pros", but sometimes chip mods have an amateurish feel to them. Please, don't wreck your systems. Leave the traces on the XP chips alone.
(posting anonymously to protect my job)
This could come in very useful when you're trying to MP-enable your chip.... or maybe you can unlock the multiplier and MP enable it at the same time? =) BWAHAHA.... Where else, but Tom's? =)
-Berj
If you read the forum discussion about the article, you'll see them saying they have had it running W2K and SysMark 2001.
Look for defroster repair paint. It'll be in a tiny bottle and is copper colored. It's got copper in it and is used to (duh) repair the copper defrogger lines on windows. It will work fine for this but it's pretty thin so be careful it doesn't run. Sometimes masking is a good idea but be careful that the "paint" doesn't wick under the tape. Just maybe use a toothpick to dab on the paint - you don't need much on there as it's a logic connection not something carrying amperage. In the past #2 lead pencils have been used for a removable solution. However this is much trickier IMO and is somthing I'd only try for test purposes.
P.S. Yeah, there are actually places that sell conductive paint but they're usually not as common as an auto parts place. I'm not sure that RatShack actually carries this stuff but I guess it would be worth a shot...
Build it, Drive it, Improve it! Hybridz.org
Since the article is more or less slashdotted, here is how to modify the chip to work on a multiprocessor board:
Complete the topmost L5 bridge if it is cut. They use conductive paint. Now the XP is detected as an MP for the multiprocessor boards.
Of course, the stability of this is questionable, and no one except yourself should take responsibility for it.
This
I have a dual Tyan m/b with two XP chips in it. It runs hot, but it's been calculating SETI@Home more or less 200% of the time since it was installed, about 3 months ago. No problems, and I think it would have found them by now :-)
:-)
Pretty soon it's going to be taken off SETI and put onto the real task, but I thought S@H would be a good reliability burn-in (not to mention adding 6-8 S@H units per day to my total
Simon
Physicists get Hadrons!
Actually the Xeons also have from 2-8X the L2/3 cache when compared to the P4. This makes a huge difference in some apps where dataset size is more important than raw crunching power. In fact on some database app's the old pentium pro's with 2MB l2 cache were faster than a normal p3's at 550 even though the ppro's were running at a slothlike 166MHz.
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
Weird shit happens when you start throwing multiprocessors made out of aluminum cans. It takes a very precise cache coherency protocol to make the whole system behave in a deterministic way. If one processor has a slight modification to the coherency protocol (say an extra delay cycle) that the other doesn't, then you're in for trouble. The chances might be one in a trillion that the differences in the protocol cause memory to become inconsistent, but consider the fact that millions of trials a second happen, it won't take long for one slight memory mistake (which will occur in the operating system during synchronization on a spinlock, most likely) to eventually bring the operating system to its knees. First it starts with two processors taking a spinlock simultaneously. Next they screw up an internal queue of processes, pages, or IO buffers. Next an IO buffer gets used by two processes simultaneously. Then suddenly they are sending two different devices corrupt data. Next thing you know some kernel driver somewhere is throwing a fit, and soon the kernel panics.
Yes, having a processor, its memory, and its cache coherency protocol validated by the manufacturer is a good thing! It is not entirely overrated, and is quite crucial. Sure a hobbled-together SMP system might work for a couple days--until something funky sneaks into kernel memory because of an inconsistency in the coherency protocol.
Now, about frying processors. You apparently aren't aware of the fact that nowadays the voltage settings of the processor are configured into the chip at manufacture time. They are chosen based on the clockspeed, intended heat dissipation, and overall, the requirements of the processor. Suppose you change the capabilities of the processor core without supplying the correct voltage. Suddenly the processor won't perform correctly because it doesn't have enough voltage to completely change internal states fast enough between cycles. Suddenly it has mysterious bugs.
Or go the other way. Suppose you screw up and misconfigure the voltage, supplying too much. Power dissipation (and heat dissipation) are proportional to the square of the voltage. Suddenly a small increase in voltage results in a lot of waste heat. Heat that could fry the processor.
Yes, bad things CAN AND DO happen when you start monkeying with those L2 bridges!
120 characters isn't enough to explain it.
I've been running to Athalon XP 1800+ 's in the dual proc board from Asus. My machine boots into WinXP Pro just fine and definately takes advantage of the dual processors (been watching cpu time and usage in the task manager) especially in 3D Studio. I just popped the chips in and the bios saw them as MPs. Does anyone know whats the min speed of the chips (1800, 1900, 2000?) that requires this mod?
BTW... I haven't had any system instability related to the dual XPs. I had serious crashes caused by the Creative drivers/spyware, and I've had problems with power (the computer drawing more than the UPS can handle and tripping it). The most important thing w/ the dual proc athalon boards is to make sure you have a 450 watt power supply (and suitable UPS) or the system will crash.
I'm out of my mind right now, but feel free to leave a message.....
That's an over-simplified view of the situation. Because the Duron's cache is smaller than the Athlon's, there will be more cache misses and there will therefore be more memory bandwidth consumed by it.
The whole idea of cache is to reduce the memory bandwidth requirements. Because the Duron is more memory bandwidth hungry than the Athlon, they will scale less well when put in dual CPU configurations.