CPU upgrade possible in 27" Core Duo imac?

[AlienSexGod]

That is false. Its a known fact the CPUs are socketed.

In that picture you can even clearly see the lever that locks it into the socket!

True but I am prety sure that pic is of a iMac Duo Core 3Ghz 775 socket

We haven't seen a pic of the Lynnfiel i5/i7 motherboard yet ... someone post please!! Unlikely but possible Apple could do something proprietary.

Till I have seen it and done it I don't believe it.

Waiting to get my hot little hands on one!!!

 

[eboleyn]

Not surprised Q9550 didn't work

After looking at the CPU specs, I'm seeing:

Supported C2D:

-- E7600: 3.06 GHz, 1066MHz bus, PCG 06, CPUID 1067Ah,
supports C1E, C2E, C3E, C4E.

-- E8600: 3.33 GHz, 1333MHz bus, PCG 06, CPUID 1067Ah,
supports C1E, C2E, C3E, C4E.

Discussed C2Q in this thread:

-- Q9550: 2.83 GHz, 1333MHz bus, PCG 05A, CPUID 10677h,
supports only C1E, 95W TDP.

-- Q9550S: 2.83 GHz, 1333MHz bus, PCG 06, CPUID 1067Ah,
supports C1E, C3E, C4E.

So, I'm not surprised the Q9550 didn't work, for any of several reasons: Different power regulator required (PCG value), CPUID info may confuse iMac EFI init SW, no support for the other CxE states, or quad-core.

The Q9550S on the other hand is the same except as an E8600 except for lacking C2E and being a quad-core, so it seems to be that it has a shot at working with at least 2 of the cores unless the EFI BIOS relies on C2E or gets confused by the quad-cores.

 

[hundert]

interesting thread, I hope someone tries.

 

[TruckStuff]

I happened to email the guys at iFixit suggesting they try this, and I got an interesting response. They confirmed that this is possible, in fact, they have successfully done it! They are still putting together the finishing details on the guide, so its not open to the public yet. They didn't specify the CPU they used, but I have asked them for more info. Who knows if they will respond. :shrug:

It would seem to me that the best upgrade option would be the Q8400s or Q9550s. Both are socket LGA775 with a TDP of 65W. My question right now is the bus speed. Both of these chips have a 1333MHz bus and the 21.5" iMacs ship with 1066MHz DDR3 RAM. Would the RAM have to be upgraded as well for best performance? I don't keep up with hardware like I used to, so I'm not sure how the bus speed would behave.

I'm willing to give this a try if the RAM doesn't need to be replaced. Replacing the RAM adds another $150 or so to the project, so its turning into a pricey upgrade instead of a nice one at $250 or so, ya know?

 

[newuser2310]

How much of a performance gain would you see with the Q9550s in the 21.5' Imac? I can find the Q9550 but not the Q9550s on sale

 

[TruckStuff]

How much of a performance gain would you see with the Q9550s in the 21.5' Imac? I can find the Q9550 but not the Q9550s on sale

According to this site, a Q9550s is more than twice as fast as the 3.06GHz C2D chip that ships on a stock iMac. Of course benchmarks are what they are: YMMV. 😉 Some other comparisons:

+ The E8600 (upgraded C2D chip) is about 20% faster than the standard C2D chip (E7600)

+ A Q8400s is almost 75% faster than the E7600

+ A Q9550s is about 65% faster than the E8600

+ A Q9550s is about 17% faster than a Q8400s

IMHO, the Q8400s offers the best performance to value ratio. The Q8400s runs about $250, while the Q9550s runs about $350. To me, an additional 20% isn't worth $100. Just my .02.

The low voltage models are more expansive than the standard voltage models (65W TDP vs 95W TDP). They are tricky to find, as Google wants to show you the more popular/common Q9550 model, but you can find them. Google Shopping links for the Q9550s and the Q8400s.

The more I write about this, the more I want to do this... if someone could answer my RAM question. 😀

 

[newuser2310]

According to this site, a Q9550s is more than twice as fast as the 3.06GHz C2D chip that ships on a stock iMac. Of course benchmarks are what they are: YMMV. 😉 Some other comparisons:

+ The E8600 (upgraded C2D chip) is about 20% faster than the standard C2D chip (E7600)

+ A Q8400s is almost 75% faster than the E7600

+ A Q9550s is about 65% faster than the E8600

+ A Q9550s is about 17% faster than a Q8400s

IMHO, the Q8400s offers the best performance to value ratio. The Q8400s runs about $250, while the Q9550s runs about $350. To me, an additional 20% isn't worth $100. Just my .02.

The low voltage models are more expansive than the standard voltage models (65W TDP vs 95W TDP). They are tricky to find, as Google wants to show you the more popular/common Q9550 model, but you can find them. Google Shopping links for the Q9550s and the Q8400s.

The more I write about this, the more I want to do this... if someone could answer my RAM question. 😀

The Q8400s is around £180 ish and the Q9550s is around £100 more in the UK

So on that basis I would go for the faster processor and not bother chopping the 21' in for an i7 until that gets an upgrade.

🙂

 

[newuser2310]

Any update on this?

http://www.ifixit.com/Guide/Repair/Installing-iMac-Intel-21-5-Inch-CPU-Replacement/1859/1

CPU replacement for the 21', no details on what cpu they used and if the quad upgrade is possible.

Cheers

 

[Nihilvor]

Yeah, looks like they did it on the 21.5. It would be nice if people made more 21.5/27 or simply some "[upgrade] late 2009 imacs" threads, as useful information for 21.5 owners gets hidden in so many of these 27" threads on SSD upgrades, graphics cards, and Core 2s.

Any update on this?

http://www.ifixit.com/Guide/Repair/Installing-iMac-Intel-21-5-Inch-CPU-Replacement/1859/1

CPU replacement for the 21', no details on what cpu they used and if the quad upgrade is possible.

Cheers

 

[Tom Sawyer]

I recently downsized from a 2.8ghz octomac to the 21.5" iMac, 4670 Ati Model (which I'm really loving, nice to have my desk back!) but of course the urge to tweak never leaves once you start. I've built countless PC's starting from back in '95 with a 100 mhz Pentium so it's kind of hard not to think of how to make a computer better. It all started with the Amiga, but I digress... 😉

In '07 I did (presumably) the first write-up on how to upgrade the hard drive in the Aluminum 24" iMac that had just been released (24" iMac HD Upgrade). After having 8 cores in my MP, I am definitely liking the idea of picking up a Q9550s and an SSD (which is the one thing I miss more than anything with the MP) and take my iMac to a different level.

That said, if I do I'll definitely be taking many pics and will post my results here first! 😀

 

[TruckStuff]

Any update on this?

I was having an email exchange with the iFixit guys about this. In it, they said that they replaced the CPU with the same model the unit shipped with. They said they are planning to do some more extensive testing of CPUs to see what works, what doesn't, but they haven't gotten to that yet. Didn't sound like they were going to get to it in the near future.

 

[samovog]

Hello!

I can confrim that the Q8400s does NOT work. I tested myself.

The machine powers up, the fans than slowly speen to full blast and there is no picture.

bummer.

 

[trance2]

I happened to email the guys at iFixit suggesting they try this, and I got an interesting response. They confirmed that this is possible, in fact, they have successfully done it! They are still putting together the finishing details on the guide, so its not open to the public yet. They didn't specify the CPU they used, but I have asked them for more info. Who knows if they will respond. :shrug:

It would seem to me that the best upgrade option would be the Q8400s or Q9550s. Both are socket LGA775 with a TDP of 65W. My question right now is the bus speed. Both of these chips have a 1333MHz bus and the 21.5" iMacs ship with 1066MHz DDR3 RAM. Would the RAM have to be upgraded as well for best performance? I don't keep up with hardware like I used to, so I'm not sure how the bus speed would behave.

I'm willing to give this a try if the RAM doesn't need to be replaced. Replacing the RAM adds another $150 or so to the project, so its turning into a pricey upgrade instead of a nice one at $250 or so, ya know?

Any further information from the iFixit.com guys? I am really, really curious if I can drop in a Q9550S in my 27" iMac.

 

[charlieroberts]

I recently downsized from a 2.8ghz octomac to the 21.5" iMac, 4670 Ati Model (which I'm really loving, nice to have my desk back!) but of course the urge to tweak never leaves once you start. I've built countless PC's starting from back in '95 with a 100 mhz Pentium so it's kind of hard not to think of how to make a computer better. It all started with the Amiga, but I digress... 😉

In '07 I did (presumably) the first write-up on how to upgrade the hard drive in the Aluminum 24" iMac that had just been released (24" iMac HD Upgrade). After having 8 cores in my MP, I am definitely liking the idea of picking up a Q9550s and an SSD (which is the one thing I miss more than anything with the MP) and take my iMac to a different level.

That said, if I do I'll definitely be taking many pics and will post my results here first! 😀

Hey did you ever get around to upgrading the processor? I have been trying to read something about it and can´t seem to fin anything.
I would love to do this upgrade.
🙂

 

[hackerwayne]

I have a 27" c2d iMac and a Q9400 no S, I assume it doesn't work right? Any updates on which C2Q S processor works?

 

[Doward]

I have a 27" c2d iMac and a Q9400 no S, I assume it doesn't work right? Any updates on which C2Q S processor works?

Here's an update: a Q9505s won't work 😉 I've got a 3.06 C2D 27" iMac in my lab right now, just tried upgrading with a 9505s C2Q I have here - no go. Fans come on, black screen, no chimes, no nothing.

 

[Dean Yu]

Here's an update: a Q9505s won't work 😉 I've got a 3.06 C2D 27" iMac in my lab right now, just tried upgrading with a 9505s C2Q I have here - no go. Fans come on, black screen, no chimes, no nothing.

....
E7600 (yes that 3.06GHz one) has A 1066 MHZ FRONT SIDE BUS BUT THE 9505s REQUIRES A 1333 MHZ FSB.......
Okay I know this thread has been there since 2009, but the fact no test of Q9550s has been performed on a freaking 3.33GHz E8600 iMac 27" is just totally, totally sad 🙁


If any one in the distant future will test it out:
1. You need a iMac Late 2009 27" with 3.33GHz E8600
2. You need a CPU with SAME TDP, SOCKET TYPE, FSB (QS series such as Q9550s)
PLEEEEEEEEEASE!!

 

[ruben253]

....
E7600 (yes that 3.06GHz one) has A 1066 MHZ FRONT SIDE BUS BUT THE 9505s REQUIRES A 1333 MHZ FSB.......
Okay I know this thread has been there since 2009, but the fact no test of Q9550s has been performed on a freaking 3.33GHz E8600 iMac 27" is just totally, totally sad 🙁


If any one in the distant future will test it out:
1. You need a iMac Late 2009 27" with 3.33GHz E8600
2. You need a CPU with SAME TDP, SOCKET TYPE, FSB (QS series such as Q9550s)
PLEEEEEEEEEASE!!

Anyone tried the Q9550s?

 

[mikehalloran]

....
E7600 (yes that 3.06GHz one) has A 1066 MHZ FRONT SIDE BUS BUT THE 9505s REQUIRES A 1333 MHZ FSB.......
Okay I know this thread has been there since 2009, but the fact no test of Q9550s has been performed on a freaking 3.33GHz E8600 iMac 27" is just totally, totally sad 🙁


If any one in the distant future will test it out:
1. You need a iMac Late 2009 27" with 3.33GHz E8600
2. You need a CPU with SAME TDP, SOCKET TYPE, FSB (QS series such as Q9550s)
PLEEEEEEEEEASE!!

If you want it that badly, knock yourself out and tell us about it.