Overclocking the Fastest iMac G3

today's perilous overclocking Shenanigans are brought to you by Squarespace but more on that in a bit this is a very special iMac G3 AT 700 MHz it's the fastest one that Apple ever released and today we're going to use my new toy soldering hot tweezers to fiddle around with incredibly tiny surface mount motherboard components to see just how fast we can overclock this thing or ruin it so stay tuned [Music] and if you enjoy tiny fragile components and the everpresent threat of irreversible damage make sure to hit subscribe the last time we had this very special iMac G3 out we were installing the latest version of open BSD that's right a fully modern operating system that still supports this ancient architecture if you want to see those experiments and learn more about this particular machine check out that video right here but for our experiments today I've reinstalled Mac OS 10.4 tiger mainly because I'd like to take some geek bench benchmarks I also want to see how much faster it runs a very special version of Minecraft I mean unless I absolutely murder this thing with these inexpensive tweezers now if you look past the fact that we're dealing with incredibly tiny surface mount components this should actually be a very easy overclock in fact there's a really great video from renoa that really gave me the confidence to try this out for myself I'll link that down in the description below now taking this thing apart should actually be pretty easy mainly because I never really finished putting it back together from the last time we took this apart got the old LTT screwdriver yes I did buy this with my own money and the PLL resistors are actually right here there's four of them a little hard to see let me put on my special bubbles glasses so these are the four resistors that we need to adjust to control the speed of the CPU and you can see there is a high and a low and basically this is binary so high is one low is zero and again thanks to the renoa video we can see what the binary values are for different multipliers now I do actually want to take the board out so I can repaste the CPU as well since we are going to be putting some more power through it dinky little thermal pad on there so I'm going to clean this CPU up with some isopropyl alcohol and then I I think I'm just going to use some new thermal pad because the old thing was a thermal pad and I want to make sure that we don't have any Gap in between thermal paste and the other side of that aluminum now according to the data sheet these are set for a 7x multiplier which makes sense because this is the 700 mahz version and the bus speed is 100 so 7 * 100 is 700 so I'm going to set this to 7.5x which hopefully gives us 750 just need to power up our fancy tweezers and I just need to move two of these to change it to a binary one from a binary 2 all right a little bit finicky I uh wish the Twee prongs were a little thinner but I suppose that's something I can probably find in any event we got there in the end and I think it's time to see if we have completely destroyed this thing right after this word about today's sponsor Squarespace create a fast beautiful and Rich web experience for your business or brand using squarespace's powerful all-in-one platform it's really easy to get started like say I wanted to build a website dedicated to overclocking vintage Apple computers I could build it in just minutes with squarespace's new Next Generation fluid engine which features powerful drag and drop technology and enables you to customize every detail of your customer's experience on desktop and mobile that's on top of optimizing for SEO managing a mailing list watching analytics and much more so check out squarespace.com action retr today for a free trial and when you're ready to launch use code action retro to save 10% off your first purchase of a website or domain all right good old sideways boot test ah chimed all right well uh it booted let's see what our clock speed is 750 okay I'm going to take a benchmark at 750 uh mainly to see if it crashes and then we're going to try to push it even further which means I actually have to move all of these all right I think I'm getting better at this those are all connected no Bridge all right 800 mahz sideways smoke test and I'm just going to stick a little USB fan here uh just to see if we can help it out a little bit staying cool ah chimed a it's looking good oh show me that glorious 800 yes it says 800 oh my goodness all right well I guess I'm going to run the benchmarks and see if it crashes all right well the benchmarks completed and it has been running for like 15 minutes so I'm going to say this is stable we'll compare all the benchmarks when we find the limit of this thing but do we dare push further we dare all right once again sideways smoke test it chimed no way is it going to let me push it this far oh my goodness and I did it the wrong way we're running at 550 MHz ah the joys of overclocking all right resist swapped the correct way around I put it at one1 instead of 0110 but fix that and sideways smoke test let's see what happens uhoh oh there it goes it chimed 450 MHz son of a gun well I guess this would be a pretty boring video if I did everything right the first time anyway let's try this higher setting for the third time huh no chime all right I've got the fan right next to the CPU now let's give this one last shot I dare say we have found the limit it does not want to do 900 and I don't think there's an option for 850 okay now before we put this thing back together I am a little bit concerned about heat I mean this CPU was nice enough to give us a whole 100 extra megahertz and this iMac famously has no fan so I do have a nice little thin 12volt fan here and uh one of these little Phantom Molex guys that's nice and small my thought is underneath the drives here there is room it looks like enough room for this fan and there's holes in there and since the aluminum back there is basically being used as a heat sink I think if we just move some air through it that can make a big difference just make sure the thing actually spins before we put everything back together beautiful ah look at that you'd never know there was a fan in there Perfect all right here we go our new 800 mahz iMac G3 100 MHz faster than the fastest one that Apple ever released and I I am quite pleased well as long as this starts up now that I've put it all the way back together hooray so the stock CPU at 700 MHz scored a 320 at 750 that was up to 340 and at 800 we have a whopping 374 that is a big difference 320 to 374 in the CPU benchmark marks in geekbench 2 and now the big question okay let's take a quick look at pre- overclock performance and we're going to do that in classic Cube which if you're not familiar it is a reimplementation of Minecraft classic in C and C++ here we are getting 11 12 frames per second honestly shockingly playable for this kind of machine all right so let's uh put this into maximized view let the world load in okay so I think we may have gained uh one or two FPS with our little experiment here which okay isn't a huge difference but you know the joy is in the numbers oh no it crashed ha overclocking okay adding on to our cooling solution I have this USB fan which I'm going to sit over top of these Vents and plug into USB here so we can really suck the air out of here and try to keep it cool all right well the good news is it seems a lot more stable the bad news news is it's much louder but I think we probably can chalk this up to Thermal Management on this overclocked CPU and since uh it seems that fans at the top of the case drawing air out makes a difference maybe I can take this top case off and just Mount to nice quiet noct to a fans up there okay so even though it seems like we still have some thermal issues in this notoriously fanless IMAX G3 I'm going to chalk this up as an enormous success because this thing is stable at 800 MHz 100 MHz over its fastest iteration as long as we have these fans sitting on the back of it but I don't think we're done yet because I got to talking to my friend dos dude one who gave me the idea of salvaging a faster rated G3 CPU out of an iBook Snow White so we might be able to find a 900 MHz rated CPU that will fit into this thing with some surface mount soldering and maybe even clock up to a gigahertz even better I think we might at some point in the near future wind up with a G4 iMac G3 in any event if you enjoyed this video I'd appreciate a thumbs up and if you'd like to see more Shenanigans like this please subscribe down below and thank you very much for watching and a special thanks to Alex Hoffman and JW Nicholson April white Chris bigs Chris Calderon Chris Nelson control out Reese Daniel hubard froto Jedi George rosansky Greg Crut Harris Brody James Fryman James Lori Jason peepas Jason easel Lyle truid Matthew cowall Paul Spencer Ryan Scott Cedar bomb Scott Thompson Tom Woodfin and Unknown Soldier 41 who are my highest tied patrons and all of my patreon supporters for helping make these videos possible

Channel: Action Retro

Views: 44,545

Keywords: retro, vintage computers, macintosh, apple, retrocomputing, retro computers

Id: vJ3-AzQGY0M

Length: 13min 58sec (838 seconds)

Published: Sat Dec 02 2023