jessenator
Well-known member
^^^^ For transparency: the CPU previously tested is a XC68040RC33M. so thought I'd make that clear.
E31F XC68040RC25M
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E31F XC68040RC25M
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Hey all, have not posted much on 68kMLA. It's 4:45am PST just finished reading Motorolas Designers Handbook for the 68040 (for the umpteenth time).
Somehow in thos haze, came across thos thread concerning 040 mask, CPUs on eBay, and personal experience using a few different mask, including the elusive L88M at 46MHz clock. Interesting note, have ran the CPU at up to 55MHz without fast ram enabled, with performance taking a hit. Have also adapted the Sonnet Quad doubler to test as well.
It's late, or early depending on how the wife sees it, will be back tomorrow, today, read through all post and surely learn a lot, ask one of a hundred questions, and possibly contribute a little from my own experiences.
So that's my intro.
Nite
I’ve got a cpuple of D50D and D98D ones and those have the bigger golden cap at the bottom.
Everything from E31F and newer has the slightly smaller cap. Size doesn’t differ between the E31Fs, E42Ks, K63Hs and L88Ms I got… they seem to be all the same.
Thanks for chiming in! I'm curious what your experiences and measurements are Do you have a way to measure the thermals from your tests? Also, I'm curious which machine/device you're clocking to 55 MHz, and would be most obliged if you could share those findings in this thread here. just so we can keep this one centered on the topic at hand.personal experience using a few different mask, including the elusive L88M at 46MHz clock. Interesting note, have ran the CPU at up to 55MHz without fast ram enabled, with performance taking a hit. Have also adapted the Sonnet Quad doubler to test as well.
At any rate, here's the Motorola E42K MC68040RC40
I get it. However it’s also important to note that some chips are likely fakes and therefore the temperature readings from those chips should be scrutinized and possibly eliminated.While recognizing fakes is a worthwhile effort, it really should have its own breakout thread. I'd like to steer this one back onto thermal performance of the L88M 040s (and comparing it to other versions). Also, in general, the whole point of the exercise is to eliminate conjecture as well as "feel," as both Fizzbin and myself have done. Actual measurements are wanted and much appreciated.
Thanks for chiming in! I'm curious what your experiences and measurements are Do you have a way to measure the thermals from your tests? Also, I'm curious which machine/device you're clocking to 55 MHz, and would be most obliged if you could share those findings in this thread here. just so we can keep this one centered on the topic at hand.
To me, the die looks bigger in this image. So this seems like one way to determine what version the chip is.
I agree here. I think the bottom cap isn't a sure-fire method. A part of me wishes I could thermocouple it that's well outside pracitcality. The fortune I had in accessing a $,$$$ camera for family pricing (i.e. $0) in itself a miracle. I'm not dropping those figures in the shape of a new instrument just for this.I’ve got a cpuple of D50D and D98D ones and those have the bigger golden cap at the bottom.
Everything from E31F and newer has the slightly smaller cap. Size doesn’t differ between the E31Fs, E42Ks, K63Hs and L88Ms I got… they seem to be all the same.
I'd like to test a D98D, as that was the first 100*C-tested chip. It might have a better chance of posting and/or bootingD50D XC68040RC25B
Sorry to necro this comment, Fizzbinn, but @demik brought up a good point to consider: a die-shrunk CPU might run hotter. How this relates to older dies and their thermal performance, like the D-series might be other inefficiencies in the die... many factors in this equation. Apologies if you mentioned this earlier up the thread, but did you test all of your 040s with your FLIR?…so I would have expected a real L88M to run cooler than the E31F, not sure there is another explanation. Perhaps the measurements under load would be better.
Recently purchased a fleabay 40mhz chip. Marked as:
MC68040RC40A
02L88M
S23159-001
I suspect it is really an E31F or E23G. Obviously a fake, trying to claim back through Ebay now. Do not buy from this seller:
Security Measure
www.ebay.com
Looks like someone else left interesting feedback after my purchase. I have yet to leave feedback, waiting to see how the seller handles my return first.
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