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jowaju

macrumors regular
Original poster
Mar 7, 2019
214
293
A little backstory on this project : I ordered an iMac 9,1 2009 model off eBay. Came in, it was actually a 2007 model. Seller didn't want to pay for shipping back and have to try to relist it, so I got it for almost nothing. Did a little research, the only confirmed upgrades seemed to be the T9300 and T9500 if you want Mojave compatibility. Unfortunately those processors cost more than the entire unit, so I dug deeper and it appears there were several other options for compatible processors, namely the T6400 / T8100 / T8300. All 800FSB, Penryn, Socket P, 35W mobile processors. (Note there are other processors as well, find the full list here : https://en.wikipedia.org/wiki/List_of_Intel_Core_2_microprocessors#"Penryn",_"Penryn-3M"_(standard-voltage,_45_nm)

Unfortunately no one has listed any of these as having been tried on the 2007 iMac 7,1. The T6xxx series are VERY cheap, the T6400 can be had on eBay for under $3.50. The T8100 is about $7, while the T8300 is around $25. The 6xxx series is only a 2MB cache, so while it was tempting to get the cheapest, I went for the T8100, with 3MB cache, 2.1Ghz clock speed and around $7.

I spent about 40 minutes taking the iMac apart and changing out the processor. (I'm admittedly no pro at taking them apart. It would have been less than 30 minutes had I not misrouted the SATA cable and had to take it back apart again to fix that halfway through re-assembly.) While I was there I cleaned the fans and blew out the inside (11 years worth of dust it appeared).

After re-assembly, the processor shows as a 800Mhz Core 2 Duo but benchmarks correctly. As you can see if it pretty much identical speedwise to the T7300 that came out of it. The 800Mhz appears to be just a symptom of the fact Apple never put a T8100 in any machine from the factory. The T8300 WAS an Apple Processor, so it would likely show up correctly in About This Mac.

Before upgrading the processor, a working patched Mojave USB installer would not even begin to boot on this machine. It would show the Apple logo and nothing else, no bar, no progress, no nothing. After the CPU upgrade, it works fine. Boots normally and installs normally. After installation and running the patcher, everything works (except backlight control, see below) including Wifi, Bluetooth, Siri, iSight Camera, DVD Playback, Video Acceleration, etc.

Per this post, I replaced the single file, took ownership, and rebuilt the Kextcache and voila, native backlight control is working. https://forums.macrumors.com/thread...ed-macs-thread.2121473/page-679#post-27615822

This machine had 2GB and a small 64GB Vertex SSD. I did upgrade to 4GB ram and even tried 6GB ram, but the difference from 4-6 was not worth the cost in my opinion. A single 4GB DDR2 SoDimm is about $35 currently, while a 2x2GB kit is around $10. The system is VERY usable with 4GB and an SSD.

Finally I decided to try my luck and install Catalina as well. Downloaded and created a full USB installer, booted to the installer and manually updated Filesystem to APFS, then performed an in place upgrade. The patcher installed Catalina, all the patches, and the APFS booter all by itself and everything worked perfectly. Lost backlight control and didn't try to fix it, but everything else appeared to have worked flawlessly with Catalina, on a 2007 iMac! Pics attached below for posterity.


Photo Aug 11, 8 00 13 PM.jpg Photo Aug 15, 6 06 39 PM.jpg Photo Aug 15, 8 20 02 AM.jpg Photo Aug 15, 8 21 48 AM.jpg Photo Aug 15, 9 13 53 AM.jpg Photo Aug 16, 12 54 44 PM.jpg
 

jowaju

macrumors regular
Original poster
Mar 7, 2019
214
293
The following processors appear to be compatible with the 2007 iMac AND allow the use of Mojave / Catalina:

T6400 - C2D - 2.0 GHZ - 2MB L2 - 800FSB - 35W
T6500 - C2D - 2.1 GHZ - 2MB L2 - 800FSB - 35W
T6570 - C2D - 2.1 GHZ - 2MB L2 - 800FSB - 35W
T6600 - C2D - 2.2 GHZ - 2MB L2 - 800FSB - 35W
T6670 - C2D - 2.2 GHZ - 2MB L2 - 800FSB - 35W
T6900 - C2D - 2.5 GHZ - 2MB L2 - 800FSB - 35W
T6970 - C2D - 2.5 GHZ - 2MB L2 - 800FSB - 35W

T8100 - C2D - 2.1 GHZ - 3MB L2 - 800FSB - 35W
T8300 - C2D - 2.4 GHZ - 3MB L2 - 800FSB - 35W

T9300 - C2D - 2.5 GHZ - 6MB L2 - 800FSB - 35W
T9500 - C2D - 2.6 GHZ - 6MB L2 - 800FSB - 35W

X9000 - Core 2 Extreme - 2.8 GHZ - 6MB L2 - 800FSB - 44W
 

EmlynDewar

macrumors regular
Aug 17, 2011
156
83
Chengdu, China
Is the SATA speed limited to 1.5Gbps on these? It's the only sore point I have running my ancient 2008 MBP.
Cool that you're dragging it into the modern era. A 12 year old computer!

What do you use it for?
 

mikehalloran

macrumors 68020
Oct 14, 2018
2,094
622
The Sillie Con Valley
Is the SATA speed limited to 1.5Gbps on these? It's the only sore point ...

What do you use it for?
Why a sore point? It’s still faster than a SATA III SSD. You do have to be careful that any SSD is backwards compatible — some are; some aren’t.

To the OP, you did replace the NV RAM battery while you were in there, right?
 

EmlynDewar

macrumors regular
Aug 17, 2011
156
83
Chengdu, China
1.5Gbps SATA 1 speed, not 1.5GBps.
SSD is still way faster than mechanical on this port, but it's a needless restriction on a chipset that supports faster.
 

jowaju

macrumors regular
Original poster
Mar 7, 2019
214
293
Is the SATA speed limited to 1.5Gbps on these? It's the only sore point I have running my ancient 2008 MBP.
Cool that you're dragging it into the modern era. A 12 year old computer!

What do you use it for?

No, you can see in the 2nd picture top right the negotiated link speed is 3 GBPS. Here's another one from Catalina showing the Link Speed and throughput. Remember this is a crappy, old 64GB SSD! Photo Aug 20, 3 12 40 PM.jpg
[doublepost=1566332146][/doublepost]
Why a sore point? It’s still faster than a SATA III SSD. You do have to be careful that any SSD is backwards compatible — some are; some aren’t.

To the OP, you did replace the NV RAM battery while you were in there, right?

I did not replace anything while I was inside other than the processor. Should I have?
 

mikehalloran

macrumors 68020
Oct 14, 2018
2,094
622
The Sillie Con Valley
I did not replace anything while I was inside other than the processor. Should I have?
Yes. It's easy. Use a CR2032 battery from the drug store instead of the high-heat BR2032 that Apple uses.

Lift the bezel and you'll see it on the right. Do not pry up—poke a toothpick or such through the slot and it will pop up so you can put the new one in. If you accidentally crack the flange anyway (it happens), put a piece of tape over the top, then a small piece of foam rubber between the battery and bezel to secure it.

When the battery gets too low, it can cause a black screen or weird artifacts on boot up, settings won't be retained, other issues. All over a $3 battery.
 

Anndra Mac Searrach

macrumors newbie
May 22, 2020
1
0
Awesome article. When you upgrade to Mojave (and then Catalina), how was the display performance?

I thought I read somewhere else that the display performance wasn't so good and that it was a little unusable due to the lack of graphic processing in the iMac7,1.

I was maybe considering getting a T8300 and using some of my (lockdown) spare-time to try and do a similar upgrade. I got mine for free and have spent £9 on a 2GB SIMM to bring it up to 4GB. Happy to spend another £10-£20 if I could get it to Mojave. Would welcome your thoughts.
 

jowaju

macrumors regular
Original poster
Mar 7, 2019
214
293
The graphics were definitely accelerated on mine in both Mojave and Catalina. I probably wouldn’t do any video editing on it, but for day to day usage it was certainly usable, especially with an SSD and 4gb ram.
 

KennyW

macrumors 6502
Sep 5, 2007
424
356
I did a similar CPU (T9500), RAM (6G), SSD (240GB) upgrade to my iMac 7,1 few yrs ago since Sierra, and it is running the latest Catalina almost as fast as my other iMac 11,1 which is running High Sierra (but not later OS due to lack of graphic support).
It has been operating very well to meet all my office work needs, web surfing, and Youtube watching.
It even meets very well my occasional gaming need, though mostly Diablo 3 (smooth enough when tuning down those high resolution settings).

Of course don't expect intense graphic or video-editing and I expect it to serve me well before the ARM Macs arrive.
 
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tanventure

macrumors newbie
Jan 17, 2013
27
3
Thank you all for many great posts! I would be considering to upgrade cpu for my iMac early "Core 2 Duo" 2.4 20" iMac8,1.

I have done 250G SSD/4G RAM upgrade, now running EI Capitan. Would like to make sure that if I can use the same CPUs, right?

Also wonder if any one has done or consider to upgrade graphics card?

thanks for sharing!
 

Nguyen Duc Hieu

macrumors 68000
Jul 5, 2020
1,511
408
Ho Chi Minh City, Vietnam
Thank you all for many great posts! I would be considering to upgrade cpu for my iMac early "Core 2 Duo" 2.4 20" iMac8,1.

I have done 250G SSD/4G RAM upgrade, now running EI Capitan. Would like to make sure that if I can use the same CPUs, right?

Also wonder if any one has done or consider to upgrade graphics card?

thanks for sharing!

Not worth the money, I guess. Compatible cards for that model are rare, expensive and weaker than upgradable GPUs for late 2009 to 2011 models.
 

tanventure

macrumors newbie
Jan 17, 2013
27
3
The following processors appear to be compatible with the 2007 iMac AND allow the use of Mojave / Catalina:

T6400 - C2D - 2.0 GHZ - 2MB L2 - 800FSB - 35W
T6500 - C2D - 2.1 GHZ - 2MB L2 - 800FSB - 35W
T6570 - C2D - 2.1 GHZ - 2MB L2 - 800FSB - 35W
T6600 - C2D - 2.2 GHZ - 2MB L2 - 800FSB - 35W
T6670 - C2D - 2.2 GHZ - 2MB L2 - 800FSB - 35W
T6900 - C2D - 2.5 GHZ - 2MB L2 - 800FSB - 35W
T6970 - C2D - 2.5 GHZ - 2MB L2 - 800FSB - 35W

T8100 - C2D - 2.1 GHZ - 3MB L2 - 800FSB - 35W
T8300 - C2D - 2.4 GHZ - 3MB L2 - 800FSB - 35W

T9300 - C2D - 2.5 GHZ - 6MB L2 - 800FSB - 35W
T9500 - C2D - 2.6 GHZ - 6MB L2 - 800FSB - 35W

X9000 - Core 2 Extreme - 2.8 GHZ - 6MB L2 - 800FSB - 44W

can the above CPUs be used for upgrading early 2008 20” iMac?

thanks
 

im_to_hyper

macrumors 65816
Aug 25, 2004
1,289
292
Pasadena, California, USA
So, you are talking about GPU, how about CPU upgrading? T8100 on eBay is only a few $.

The Radeon 2600 Pro would be an OK upgrade, especially for playing older titles under bootcamp!

If the CPUs is removable, why not?
Go for T9500 or higher, depending on availability. T9900, perhaps?

The socket P CPU needs to be compatible in terms of FSB support. The T9300, T9500 and X9000 CPUs have the correct FSB speeds (800MHz) for these models.
 

iMacUser2007

macrumors newbie
Jan 22, 2021
8
4
Hey guys, so tomorrow I'll be doing the upgrade to a T9300 and I was asking myself: did anybody try to update the 2007 iMac to Big Sur yet? According to dosdude it should be compatible! Any experiences you can share?
 

im_to_hyper

macrumors 65816
Aug 25, 2004
1,289
292
Pasadena, California, USA
Hey guys, so tomorrow I'll be doing the upgrade to a T9300 and I was asking myself: did anybody try to update the 2007 iMac to Big Sur yet? According to dosdude it should be compatible! Any experiences you can share?

I mean, I can try for you if you'd like, but I think Mojave will be the way to go. Otherwise that GPU will sit unused and that CPU will be doing all the rendering.
 

iMacUser2007

macrumors newbie
Jan 22, 2021
8
4
I mean, I can try for you if you'd like, but I think Mojave will be the way to go. Otherwise that GPU will sit unused and that CPU will be doing all the rendering.
Thanks for the response! I installed Mojave HFS and it's running great – so I won't update to Catalina/Big Sur as long as it's working just fine as it's a Mac I rely on atm. Installing Big Sur would be just out of curiosity to see how it performs ;)
 

boxtop

macrumors newbie
Apr 20, 2021
1
0
Awesome thread - I trash-picked up an iMac 7,1 to use as my workshop computer for repair lookups, music, etc. Replaced the dead HD with an inexpensive 128G SSD, blew the cobwebs and dust out, installed El Cap and have been humming along. Was looking to modernize it & came across this thread - just ordered a T8100 for $14 shipped & 2 2G SODIMMS for $20 shipped - looking forward to building it up, replacing the PRAM batt & installing Mojave via patched USB installer.
 

creaturemangler

macrumors newbie
Sep 24, 2021
2
0
I also am trying to complete the upgrade on my mid 07 iMac with a new t8100, but my Mac will not POST, chime or display video signal. The diganostic LED's show 3 out of four, meaning it is a problem with the either the video card or display, but when I reinstall the original CPU everything works straight away.
The guy who sold me the CPU on Ebay swears that he tested it - and is evidenced by the paste that was still half on it upon opening.
Do you have any tips that I could use as to why my machine wont post with a t8100 but will with the standard CPU?
Awesome thread - I trash-picked up an iMac 7,1 to use as my workshop computer for repair lookups, music, etc. Replaced the dead HD with an inexpensive 128G SSD, blew the cobwebs and dust out, installed El Cap and have been humming along. Was looking to modernize it & came across this thread - just ordered a T8100 for $14 shipped & 2 2G SODIMMS for $20 shipped - looking forward to building it up, replacing the PRAM batt & installing Mojave via patched USB installer.
 

Mac_Noob80

macrumors newbie
Nov 2, 2021
3
0
Yessir, El Capitan is up to date and the EFI firmware is the latest!
I'm having kind of a similar issue where I upgraded the CPU to a T9300 (iMac mid 2007) and now when I try to upgrade to El Capitan it just sits at a light gray screen with a progress bar about 2/3 complete. Should I have updated to El Capitan before I upgraded the CPU?
Where you ever able to get your device updated?
 
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