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Well, I have an iMac 20’’ ( ver. 7,1 - Late 2007 ). My CPU is a T7300 @ 2.0GHz. Can I upgrade the processor to C2D Extreme X7900 @ 2.8GHz ? Update It’s all ok! :-) I work with iMac 8 hours per day and don’t have any problem! It’s totally recomended to change the CPU ! I install Lion and works perfectly.

Yes! I was able to swap out the processor on my T7300 20" mid 2007 imac to an X7900 by following the instructions for replacing the heatsink here: iMac Intel 20" EMC 2133 and 2210 Heat Sink Replacement When the heatsink is removed, the CPU is exposed. Turn the slotted screw on the socket 180 degrees to release the CPU and install the X7900. I do have a caveat: The connectors on the wifi and bluetooth antennas are extremely delicate and hard to get off/on. I just unscrewed the daughter boards, there is enough slack to leave them attached to the antennas. After the install and reassembly, the computer booted up fine, there were no settings to make, firmware flashes or any other special procedures, just turn it on and bask in the glory that is the Core 2 Duo extreme. Update Yeah, it runs just great. No heat issues or any glitches. The 64-bit geekbench score when from 2749 to 4239, an improvement of 54%. I also put a 4GB in one slot and a 2GB in the other for 6GB total RAM.

Well its done! The T9300 is in and macOS Sierra is running smoothly on my 2007 iMac. It does benchmark a little less than the X7900 but the T9300 runs much cooler. I will like to give it more time before I say for sure but I am thinking that it runs macOS better than the X7900. Im not experiencing beachballs or lags like I was on El Capitan. If anyone wants any more info just let me know. Im gonna work on it a few days and see how the experience is all around. And then do a final impressions in about a month

I know this is an old guide, but just wanted to post that I just upgraded my old 20" iMac EMC 2133 from a 2.0 GHz T7300 to a 2.6 GHz T7800 and it works great. The T7800 was never officially offered in the iMac, but it was offered in the MacBook Pro of the same era, so the OS and firmware seem to know about it. Right now a used T7800 goes for about $21 while the X7900 still sells for $70, so it seemed like a good deal coming from 2.0 GHz. At the same time, I upgraded the original (probably failing) hard disk to a 480 GB SSD. Running 10.10 the machine has gone from unbearable to actually useful for daily work. Pretty awesome for a 9 year old computer and bought me time to save up a little extra to upgrade to a Retina iMac instead of the standard res I would have bought today if the upgrade didn’t work. Edit - as requested, here is what my system profiler shows post-upgrade:

And here is an image of the iMac all torn apart. This isn’t an upgrade for beginners, but it’s not really any harder than doing a logic board swap in most laptops - you just need the Torx drivers while most PC laptops stick with Phillips.

Finally, here is the new CPU in its socket before thermal paste.

Just to update, its almost 4 years later that I posted here and the x7900 is working great for El Capitan. But I am moving on. I just ordered an E8135 cpu and am going to be installing it soon so I will then be able to install macOS Sierra on my 20" 2007 iMac. I am also going to be doing a wifi/bluetooth upgrade with a combo card out of a 2013 MacBook Pro. UPDATE********* The E8135 does not work. I think its because the FSB on the E8135 is 1066 and our 7,1 iMac FSB is only 800. I tried a few things but never got it to boot up completely, I am waiting on a T9300 now. which has the same FSB and supports sse4.1 for macOS Sierra. I will keep this thread updated when the parts come in on the 17th. Im also upgrading the wifi/bluetooth to a combo card from a 2013 MacBook Pro. So it should support handoff and continuity.

It depends on the system’s firmware and the EFI firmware limitations Apple has imposed. Technologically it should work if the chipset agrees with it seeing as it’s just LGA775 and Apple’s pinout for it is no different from how everyone else does it. Since there is no official support for the EE CPU series it may not work.

I inherited an old iMac (A1224) mid-2007 20" Core Duo 2 2.0GHz, with the rock-bottom specs for this model. I first bumped the RAM from 1GB to 4GB for $20. Next, I bought a X7900 (pulled from a A1225 iMac) on eBay for $59 and replaced my T7300 CPU, using the iFixit guide. (It took about 2 hours.) My Geekbench 3 (64-bit) score went from 2135 (T7300) to 2916 (X7900). While running Geekbench, the CPU temp went from 30 C up to 48 C (iStat menu). So I get about a 37% increase with the X7900 over the T7300, which is pretty much consistent with the Geekbench numbers reported on the Everymac website. I’m currently running OS X 10.8.5 on this iMac, with Office for Mac 2008 installed. Both Word and Excel run noticeably faster with the X7900. After a couple of days usage, I’ve experienced no problems with the upgraded iMac so far.

So I don’t think the E8135 will work because FSB is 1066 and 2007 20" iMac is 800. I thought it might just run it at 800 but it refuses to boot up all the way. Only $3 off eBay so no big lose. I ordered a T9300 to try next. Still a step up from the X7900 and the FSB is 800 and it supports sse4.1. Will let you guys know the results when it comes in

Also upgraded an 20" iMac 7.1 mid-2007 from a T7700 to a X7900 processor without any problem. Changed the original WD 320GB harddisk to a Samsung 830 SSD (128GB). Did’nt test benchmarks, but the system seems to work remarkable faster & because of the SSD the system becomes extremely quiet !

Has anyone tested the iMac7,1 with any of the following Socket P chips? I selected chips that were “extreme”, quad core or had a clock speed higher than 2.6GHz.

Montevina platform 2.53 GHz Core 2 Extreme QX9300 1066 MT/s 45 W 2.27 GHz Core 2 Quad Q9100 1066 MT/s 45 W 2.00 GHz Core 2 Quad Q9000 1066 MT/s 45 W 3.07 GHz Core 2 Extreme X9100 1066 MT/s 44 W 3.07 GHz Core 2 Duo T9900 1066 MT/s 35 W

Santa Rosa/Santa Rosa Refresh platform 2.80 GHz Core 2 Extreme X9000 800 MT/s 44 W 2.80 GHz Core 2 Extreme X7900 800 MT/s 44 W 2.60 GHz Core 2 Extreme X7800 800 MT/s 44 W 2.60 GHz Core 2 Duo T9500 800 MT/s 35 W 2.00 GHz Core 2 Duo T7300 800 MT/s 35 W

The QX9300 will not boot on an iMac8,1.

Source: http://www.dslreports.com/forum/r2737176…

A Q-Spec (qualification) X9000 will boot on an iMac7,1 but will underclock the processor to 400MHz and benchmark reflects a slower processor. No S-Spec (shipping) processor has been tested as of this writing.

Source: http://hexus.net/tech/features/systems/1…

A T9500 will boot on an iMac7,1 but “System Report” reports that the processor is 700MHz with a 400MHz FSB. Xbench reflects a part faster than the original T7300 that was installed.

Source http://forums.macrumors.com/showthread.p…

- So the confirmed working parts on the iMac7,1 are the following

2.80 GHz Core 2 Extreme X7900 800 MT/s 44 W 2.60 GHz Core 2 Duo T9500 800 MT/s 35 W

I would love to include the 2.80 GHz Core 2 Extreme X9000 but no one has yet upgraded to a shipping part of this product yet. While searching for a X7900 on eBay the seller was writing that he will be upgrading to a X9000 for his Dell M6300. I know it isnt an Apple product but they share the same Santa Rosa platform. I am just doing preventive maintenance research in the event that I have to replace the HDD of my iMac in the future. May as well install a better processor with a faster HDD. May even swap out the MXM if it is feasible.

Hi All, FYI, I’ve “upgraded” my iMac 7.1 (Mid 2007 imac 24’ 2.4ghz - T7700 intel chip) to an X9000 chip. Result : iMac working and fully functional but slower than with the original T7700 chip (geekbench results : 1850 with X9000 and 3350 with T7700). Looks like the chip indeed is working at 400ghz, and that it’s not only an “about this mac” report bug. I tend to think that the Apple EFI / BIOS does not properly recognize the chip because it’s never been written for it (The X9000 chip has never been officially listed in the iMac range). => back to original configuration…. Sorry guys…

I upgraded my iMac 8,1 from a 2.4ghz E8135 to a 3.06ghz T9900 http://browser.primatelabs.com/geekbench…

This thread is great! I installed an SSD in our iMac7,1 in 2012, and it has been the kids’ workhorse, and a piano (USB 88-key keyboard), ever since. During that project, I also installed a C2D on the first-gen 2001 iMac. Need Penryn for macOS Sierra, the Santa Rosa refresh. Ordering my T9300….

Hello!! I started a new thread here: replacing X7900 to T9300 for macOS Sierra install Is it worth it? Its more about the T9300 and macOS. I thought it was time to move since this one seemed to be getting cluttered and the topic has moved from the X7900 to the T9300. If you have questions or concerns I think we should direct them to that thread Nandor690

Thanks for the reply. I was kinda worried about something burning up since it pulls about 12 more watts. The lady I bought it from upgraded to a 27" iMac and she had a lot of money. She told me she didn’t really care what she got for it so I offered her $200 and she took it.

I’m not for sure the types you’re mentioning are socket 478 one’s. This is a limmiting factor in the 7.1 iMac of course … Otherwise: if the processors dissipated power is about 35-45 Watt I would give it a try ! Frank.

Hi All, I heard that Core 2 Extreme QX9300 doesn’t work on imac 2008 (imac 8.1), How about Core 2 Extreme QX9300 on iMac 2009 early model? I am currently using iMac 2009 early model with Core 2 2.66ghz(e8135) and I am planing to upgrade my CPU. There are two CPUs (e8435 and qx9300) that I can choose. I don’t really know how much differences between e8435 and e8135 (3.06ghz and 2.66ghz), but I believe 4 cores always better than 2 cores(qx9300 vs e8135).

I finally sold my X7900-boosted Mid-2007 imac and got a late 2012 on ebay for $800. Time to move to the next level! I’ll look at swapping the 2.9Ghz i5 with an i7 and report later. I got as much speed and work out of the old girl and I think is economically via, but it’s time to move up to something that’s supported a little better by the new OS X Mavericks.

Here is a better link on replacing the CPU. I got a hold of a donated iMac 6,1. Bought a Samsung 250 GB SSD (840 EVO) and replaced one of the memory card to a 2GB, for a total of 3GB. I’m looking to replace the CPU to X7900 and to 6 GB with a firmware upgrade. iMac Intel 24" EMC 2111 CPU Replacement

Thermal design power of the T7300 is 35W, while the X7900 does a 44W. So yes: it may become warmer (or the cooling fans wil work harder). On the other way: your SSD draws less power than a conventional harddisk. My 7.1 is upgraded since 2012 (X7900 + Samsung SSD) and I’ve experienced no problems (24/7 in use). Don’t expect to much advantage: benchmark of the T7300 is ‘1199’ while the X7900 reaches ‘1704’.

A 3.07 GHz 6MB Core 2 Duo E8435, appears to also work in these macs. I believe the CPU is slightly faster than the X7900. I did the exact same upgrade mentioned in iMac 2008 20inch - CPU upgrade

I successfully did it. Toady i finally tore apart my 20inch iMac and replaced the 2.66 ghz CPU with a 3.06 one. It runs, and the replacement of the conductive compound looks like making the heatsink work better. LOOKS….

Hello, I’m sorry for resuming an old thread, but i recently tried to do this upgrade; I have an iMac mid 2007 20” with an intel T7300 cpu, but after the upgrade to an X7900 cpu the iMac do not want boot. I opened and re-closed the Mac many times for checking if i reconnected in a wrong way some connector, but nothing changed; Then i tried to power up the iMac without the front case for checking the 4 internal led and i noticed that the 4th stay off, so I checked the lcd connector many times, but no way to solve the problem. When i press the power botton this happend: I heard the ODD’s sound, The cpu fan try to spin but it don’t do it, no chime sound, the first 3 led turn on and the 4th not, black screen and nothing more. After two days, i decided to replace the new cpu with the old one and the system suddenly restart to work. What’s going on? It’s the new cpu that doesn’t work or my iMac do not support it? Apologise me for my bad english.

Ciao Simone and everybody, did you make any further CPU upgrade attempts? My iMac 7.1 24" urges a CPU upgrade, X7900 at the moment, and a choice between T9500 and X9000 has to be made. I read about upgrade to X9000 failed attempts, but:

  • it’s not clear if X9000 used was an S-Spec
  • the original CPU was not a X7900 like mine
  • macOS version on tested iMac was very old and not the newest available (10.11.6 El Capitan). These are details which could make a difference between a failed and successful attempts. To summarize, I’d like to know if anybody tried to upgrade an iMac 7.1 24" CPU X7900 os X El Capitan 10.11.6 system to CPU X9000 S-Spec SLAZ3. Thanks in advance, Marco