how to over-clock intel core 2 duo

gunsbycomputer

macrumors newbie
Original poster
May 10, 2010
5
0
i have an imac Late 2006 - 24" 2.16 ghz - MA456LL with memory 4gb(2X 2gb of ddr2 sdram cas4).

0ver the weekend, i bought a t7600g. i also recently bought a new graphics card (NVIDIA GeForce 7600 GT) and plan install it on 5/14/2010 or 5/15/2010. i have a couple questions perhaps you will have some answers.

the t7600g (cpu) (2.33-3.16 ghz; with a sweet spot of 2.8ghz) has an unlocked clock multiplier (14.0X-19.0X) with an Operating voltage: 1.0375-1.3000V is there any way to tap into this potential once the chip is installed? how do imacs determine the speed of their cpu? if its not possible to alter the chip speed, its base power of 2.33 is ok. i hear the t7600g's sweet spot is 2.8 ish.

any idea of what type of performance increase i can expect from my imac by upgrading (cpu) a t7400 socket m to a t7600g socket m, and graphics card upgraded NVIDIA GeForce 7300 GT to NVIDIA GeForce 7600 GT?

i have the following imac items in working perfect order. i just wanted a faster computer for logic pro and iphoto so i swtched them out for upgrades. are you interested in me sending them to you and you offering me $$ after testing them? you name the price. something is better than nothing.
2 X intel core2duo t7400 socket m (LF80537) - cpu
1 X NVIDIA GeForce 7300 GT to NVIDIA GeForce 7600 GT (apple part #661-479) - graphics card


if you can answer any of my questions great. if not no big deal. please let me know your thoughts.


aloha
matt schreiber
 

Hellhammer

Moderator emeritus
Dec 10, 2008
22,076
580
Finland
Macs don't have BIOS is a lot harder. First of all, it's impossible under OS X, so you need to install Windows. There are some overclocking utilities for Windows which you can use. Keep in mind that the overclocking only works in Windows so when you're back in OS X, you're running at the original speed.
 

gunsbycomputer

macrumors newbie
Original poster
May 10, 2010
5
0
thanks for the help. i wasn't sure if bootcamp would work on the mac side. that clears that up. does anyone know much about imacs open firmware? is there a kernel that would help? what determines the cpu's speed in a imac?
 

Hellhammer

Moderator emeritus
Dec 10, 2008
22,076
580
Finland
thanks for the help. i wasn't sure if bootcamp would work on the mac side. that clears that up. does anyone know much about imacs open firmware? is there a kernel that would help? what determines the cpu's speed in a imac?
Theoretically, it could be possible. I'm pretty sure EFI (aka Mac BIOS) determines the CPU speed but the issue is that you can't access it. Maybe there is a way to access it, I don't know. Reason why there is no overclocking utility might be that most Macs are already hot and can't really be overclocked due heat. Also PSUs might not be able to handle it
 

gunsbycomputer

macrumors newbie
Original poster
May 10, 2010
5
0
white flag

ok i surrender! all of you hints are all i have also discovered in the last two weeks. i was also told my cpu is a laptop variety and they dont respond well to overclocking. but if anyone knows something i dont please share it with me...i geek benched my machine and i received a 3025. i can wait to install the cpu(t7600g) and video card geforce 7600gt, and then see what my geek bench score is. im hoping to break 3556 that is the highest imac (late 2006) score posted.
 

Billydelp4

macrumors regular
Feb 29, 2008
102
0
ok i surrender! all of you hints are all i have also discovered in the last two weeks. i was also told my cpu is a laptop variety and they dont respond well to overclocking. but if anyone knows something i dont please share it with me...i geek benched my machine and i received a 3025. i can wait to install the cpu(t7600g) and video card geforce 7600gt, and then see what my geek bench score is. im hoping to break 3556 that is the highest imac (late 2006) score posted.
you can't swap out graphics cards with imac unless you buy a new imac
 

UltraNEO*

macrumors 601
Jun 16, 2007
4,048
12
近畿日本
Macs don't have BIOS is a lot harder. First of all, it's impossible under OS X, so you need to install Windows. There are some overclocking utilities for Windows which you can use. Keep in mind that the overclocking only works in Windows so when you're back in OS X, you're running at the original speed.

There is a tool for the macPro but it's not very good... but goes a long way to prove it's possible.

zdnet clock
 

gunsbycomputer

macrumors newbie
Original poster
May 10, 2010
5
0
i really like that mac pro application. i tried to find a way to contact the developers of zdnet clock to see if they could help but i dont speak german. go figure.what an interesting read. i was also looking into the logic board that is installed in my computer perhaps the logic board has some auto detection/settings that will optimize my setup/install. didnt find much on that. at any rate i hope to upgrade my computer this weekend.
 

ItsAddison

macrumors newbie
Oct 25, 2007
22
0
Dallas, TX
I've yet to read this thread, but I just wanted to say I have the exact same computer as you and our iMac's don't utilize 4 GB of RAM. 3GB is the max. Not sure if you knew that when you installed 4.
 

im_to_hyper

macrumors 65816
Aug 25, 2004
1,094
206
Pasadena, California, USA
Alright -- so I just wanted to post on this really old thread as it on the top of Google Search results in 2019 when looking for information as to how to upgrade this iMac, and also when looking into T7600G compatibility!

Based on a lot of stuff online; it seems that the following for this iMac holds true:

  • This 24" iMac (Late 2006) uses a custom MXMII GPU design. If you search Ebay for 661-4180 you will find the 7600 GT which is the only officially supported GPU. (Supposedly an 8800 can be used?? But that was from some random sketchy resource and yeah. Can't find any more about that....)
  • This iMac uses socket M CPUs which means that the T7600 (T7600G if you feel "risky") are the maximum supported CPUs. Upgrades to the T7600G will probably not enable software overclocking; unless you can track down that old clock generator utility for the Mac Pro and see if it works. The T7600 seems to be a bit cheaper on Ebay, however! :)
  • You can use MacPostFactor to install Mountain Lion (10.8), Mavericks (10.9), Yosemite (10.10), or El Capitan (10.11). Graphics acceleration is going to be... spotty at best with the legacy GPU. (If you can magically make an 8800 GT MXM II card somehow work then, well, more powah to ya... though that seems like it would work a lot better with graphics acceleration in El Capitan)
  • Due to this being a Socket M processor, newer CPUs like the T9300 (Socket P) simply will not work. That means that Sierra, High Sierra, Mojave, Catalina, etc simply cannot be installed as they require SSE 4.1 which these CPUs simply do not have. It does not seem that there is a workaround nor will there ever (I can eat my words if proven wrong)
  • You can replace the hard drive with an SSD, and you can replace the optical drive with additional storage.
  • 4GB DDR2 PC2-5300 (667MHz) RAM can be installed when using the following link to the iMac 1.2 Firmware upgrade. https://support.apple.com/kb/DL205?viewlocale=en_US&locale=en_US (may someday be a dead link)
  • If the display needs to be replaced due to scuffs, etc the original display is an LM240WU2-SLA1. (As a fun note; there are controller board converters for you to use your old scuffed panel for your fun "smart mirror" or other projects)
In my case; this Late 2006 24" iMac is going to have:

  1. New Display ($80 in 2019 USD)
  2. 7600 GT upgrade ($70 in 2019 US Dollaroodaleedoodles)
  3. 4GB DDR2 RAM ($15 in 2019 US Derkers)
  4. 1TB Crucial MX300 SSD (mounted with a 2.5" to 3.5" adapter)
  5. 2TB Seagate 2.5" HDD (in the superdrive slot)
  6. External Blu-Ray Burner (I use optical media in additional to external drives and cloud storage to make backups of music, photos, movies, etc)
  7. Triple Boot Windows 10 64-bit for my legacy Windows games w/full 3D acceleration; Snow Leopard 10.6 (for my PPC software and older Mac software + full 3D acceleration), El Capitan 10.11 for day-to-day usage (limited 3D acceleration but will handle HTML5 videos, etc fine).
----

I mean. Yeah. $275 in upgrades is dumb when you could buy a better, used iMac for the same amount. BUT if you want to upgrade your iMac, then you are here because you searched and this is the thread you already found, and you don't need people telling you that "it makes no sense".

So anyway. Here we are! Yey for google.

i have an imac Late 2006 - 24" 2.16 ghz - MA456LL with memory 4gb(2X 2gb of ddr2 sdram cas4).

0ver the weekend, i bought a t7600g. i also recently bought a new graphics card (NVIDIA GeForce 7600 GT) and plan install it on 5/14/2010 or 5/15/2010. i have a couple questions perhaps you will have some answers.

the t7600g (cpu) (2.33-3.16 ghz; with a sweet spot of 2.8ghz) has an unlocked clock multiplier (14.0X-19.0X) with an Operating voltage: 1.0375-1.3000V is there any way to tap into this potential once the chip is installed? how do imacs determine the speed of their cpu? if its not possible to alter the chip speed, its base power of 2.33 is ok. i hear the t7600g's sweet spot is 2.8 ish.

any idea of what type of performance increase i can expect from my imac by upgrading (cpu) a t7400 socket m to a t7600g socket m, and graphics card upgraded NVIDIA GeForce 7300 GT to NVIDIA GeForce 7600 GT?

i have the following imac items in working perfect order. i just wanted a faster computer for logic pro and iphoto so i swtched them out for upgrades. are you interested in me sending them to you and you offering me $$ after testing them? you name the price. something is better than nothing.
2 X intel core2duo t7400 socket m (LF80537) - cpu
1 X NVIDIA GeForce 7300 GT to NVIDIA GeForce 7600 GT (apple part #661-479) - graphics card


if you can answer any of my questions great. if not no big deal. please let me know your thoughts.


aloha
matt schreiber
There is a tool for the macPro but it's not very good... but goes a long way to prove it's possible.

zdnet clock
I've yet to read this thread, but I just wanted to say I have the exact same computer as you and our iMac's don't utilize 4 GB of RAM. 3GB is the max. Not sure if you knew that when you installed 4.