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Author Topic: Ultimate (iMac) MXM efi rom/vbios thread...  (Read 197063 times)
lion10
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« on: December 05, 2010, 07:54:30 PM »

Well, after hours, days, weeks of testing and browsing around the web, - the time has come to start here a MXM related thread... Smiley

What's the exact matter? The original matter is the enormous error rate of Apple's early MXM (1Gen) based Geforce 7300 / 7600 cards. The repair (replacement) of such a card is around $600 to $700, - naturally without "lifetime warranty". Wink The possibility of the same fault after two or three years is more then likely... Sad

What are the alternatives, respectively are there any alternatives? Sure, you can buy for $249 an original Apple Geforce 7300 MXM card and DO IT YOURSELF. This will spent you some money. But, - as mentioned, the possibility of a repeat of the error after some years seems to be very likely.

Well, are there any additional alternatives? Why not use an MXM (1Gen) Radeon HD card out of the (before 2009) ALU iMac line? Yes, sounds good, but WRONG, I tested this in-depth with the result INCOMPATIBLE. The electrical / physical parameters are perfect matching, but the way how the MXM EFI is communicating seems to be different. I read somewhere that the white iMac MXM (1Gen) modules are talking to the logicboard according EFI 1.10 specification, while the 2007/2008 ALU iMac MXM (1Gen) modules are talking according EFI 2.xx, ALTHOUGH they only have EFI 1.10 level!  Angry

Note, the well discussed 32bit / 64bit EFI subject seems to be here negligible, - every MXM (1Gen) based iMac (2006/2007/2008) has 32bit EFI 1.10.
It is confirmed for MXM (1Gen), iMac 2006 are 32bit EFI based and uses UGA video protocol. iMac 2007 & 2008 are 64bit EFI based and use GOP video protocol.

First question, is there a way to change the form of "EFI communication", so that I can use an ALU iMac MXM (1Gen) card?

Second question, how looks it with "cross flashing" of standard PC MXM cards? That seems to work quite well in the matter of (standard PC) PCI-E graphics cards. It should be also possible for MXM cards, - however the aspect of hacking the ROM needs well funded skills which I don't have… Sad


Update 2012:
It seems that the original iMac MXM Geforce 7300 cards have not the same "overheating design flaw" like the iMac MXM Geforce 7600 series. As several informations trough the web indicate, - the problem is here the debased original thermal conductance paste. Apple seems to have saved money at the wrong place. Wink However, when the card is still alive, it can be saved with high quality thermal conductance paste! I can confirm this for several Geforce 7300 based 24" iMac computer which works with new thermal conductance paste again absolutely error free.

To be clear, that solution does not work for Geforce 7600 based iMacs. It seems that the Nvidia GPU has a to high overall TDP (Thermal Design Power) which cannot be cooled down in these 24" iMac systems. The Geforce 7600 card must be replaced with a Geforce 7300 one. A very similar problem has the first iMac ALU generation (2007 - 2008). Here it is recommended to replace the high end model Geforce 8800 GS with an Radeon HD 2600 one.


Update 2013:
Unfortunately, it looks like it hasn’t changed a lot here since my last post.  Wink  There seems to be no simple way in this matter.

However, the situation has somewhat worsened. It seems that the Geforce 8800GS MXM cards installed in formerly “high end” 24” ALU iMac line from 2007 to 2008 are also affected from a grave (thermal?) design flaw. They are dying recently in epidemic proportions. I had two affected iMacs the last six months; - ebay and other auction platforms are full of them. Only current solution is to buy one of these *damn* expensive Apple Radeon HD 2600 or Radeon HD 2400 MXM cards. Note, - a matching (Radeon HD) GPU heatsink (for 24” iMac) may also be needed!

Well, well, I'm start to suspect - that all these GPU related iMac "design flaws" are not just simple coincidences. I am beginning to believe that all these failures are part of a clandestine strategy from Apple. Yes, I agree, that sounds definitively somewhat paranoid….

Finally something positive; an exception may be the Radeon 6970M MXM (2Gen) cards which also seems to have increased error rates. Build are these into the 27” ALU (Unibody) iMac from 2011 to 2012. Unbelievable, - Apple has started in this case a replacement program! Smiley http://support.apple.com/kb/TS5167?viewlocale=en_US Haste is necessary, - the program ends in May 2014.
« Last Edit: December 11, 2013, 10:22:01 PM by lion10 » Logged
macster
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« Reply #1 on: December 06, 2010, 01:03:56 AM »

Maybe this could fix whatever issue you're having with the 7300GT:

http://www.flickr.com/photos/litmus/4480251432/

Do you have the defective part still?
« Last Edit: December 06, 2010, 01:05:43 AM by macster » Logged
lion10
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« Reply #2 on: December 06, 2010, 10:32:02 AM »

Thanks for this information, - I have / had a defective MXM Geforce 7600GT card. These one even died more frequently because of the additional heat and power consumption.

When I will buy a the end an original Apple card, it would be surely a Geforce 7300GT. Because my heat pipe is fully "copper based", there shouldn't be any thermal problem in conjunction with that lower end card. Well, - I hope....

The question is where to buy such a card, - until now I found only one store called "we love mac"...
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Gpzjock
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« Reply #3 on: December 06, 2010, 11:01:42 AM »

Hot GFX cards in small enclosures have always been a problem for power crazed laptop users, many iMacs suffer from the same issues being basically big laptops with vertically stacked components rather than horizontally laid out ones. My elderly G5 iMac regularly bounces off its 85ºc limiter with a feeble Radeon 9600 mobility card on its logic board, admittedly the G5 CPU runs overly hot too so it is probably more responsible for the excessive temperature.
My advice for all iMac owners is to use the traditional iMac Upgrade Kit: see attachment  Grin
After your warranty has run out the future is bleak, with repairs to any major part being expensive even if you can do them yourself. I have replaced dying hard drives in various different iMacs over the years and besides RAM upgrades this seems to be the only other economic repair/upgrade.  Angry
Save up for a Mac Pro or sell on your 3 year old iMac before it starts to malfunction and replace it with an updated beast with another 3 year Applecare warranty attached. Surprisingly enough a 3 year old iMac still commands a fair resale value compared with an equally aged PC which is just about worthless by then.


* macupgradekit.jpg (28.95 KB, 450x341 - viewed 1674 times.)
« Last Edit: December 06, 2010, 11:07:31 AM by Gpzjock » Logged
macster
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« Reply #4 on: December 06, 2010, 03:57:24 PM »

Too funny.  Cheesy

I think eBay is the best option if you want an immediate fix:
7300GT for $169

Hold onto the old part though.  I may be able to offer a fix after the holidays.
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Rominator
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« Reply #5 on: December 07, 2010, 03:49:15 AM »

A very interesting topic.

It is quite likely indeed that it is possible to flash CERTAIN MXM cards to work in various iMacs.

Any card that has already existed is a good candidate.

Problem is there has been NO reports of this having been done.

An old chum of mine named "CUDA: appeared at MR last year saying he wanted to do this. Don't think he ever got around to it.

Would be arduous to test, and we might very well run into the eternal "ROM chip not big enough for Mac EFI" issue

But the ROMs can be found, there are several in recent Mac EFI updates. I saw a bunch of iMac Nvidia ones so I know the ROMs can be had easily.

And since they were in an Nvidia flasher package for Mac Pro cards too, it seems they flash the same.

Definite opportunity here for somebody with some iMacs on hand.
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lion10
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« Reply #6 on: December 08, 2010, 10:37:27 AM »

To macster, thanks for this info, - I found also on ebay an offer for just $149! I should buy a bunch of them, - then I have some reserve for the future. Yea, I really love the idea to completely disassembly my iMac every two to three years!  Wink  Angry

To Rominator, - that's really an interesting matter. Unfortunately I lost the overview... Where I should start? All these tools work only under Windows / pure DOS. There are no such ones for OS X.

A perfect thing would be a "MXM to PCI-E graphics converter". Then I could handle it like an "normal" Graphics device (in a Mac Pro or PC)...
« Last Edit: December 08, 2010, 04:18:07 PM by lion10 » Logged
Bolle
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« Reply #7 on: December 08, 2010, 11:13:47 AM »


A prefect thing would be an "MXM to PCI-E graphics converter". Then I could handle it like an "normal" Graphics device (in a Mac Pro or PC)...

those things exist. just google a bit. might be hard to get one but they definetly are out there.
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macster
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« Reply #8 on: December 08, 2010, 05:17:19 PM »

How about bypassing the step of flashing and using EFI injection (e.g. NVenabler or GraphicsEnabler) instead? 
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Rominator
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« Reply #9 on: December 09, 2010, 04:04:14 AM »

Since Nvidia cards all require a "helper" card, this won't work for Nvidia.

For that matter, the injection method hasn't worked with ATI cards for awhile either.

BTW, if someone wants to trailblaze on this but needs a larger EEPROM on their MXM GPU, I'll do it for free.

THis is assuming that these cards use a SOIC-8 EEPROM like the desktop cards. If you pay for shippin, I'll slap a 128K or 256K chip on one of these so that someone can test. Only stipulation is that info gleaned becomes public.
« Last Edit: December 09, 2010, 04:06:41 AM by Rominator » Logged

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thugscry
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« Reply #10 on: November 14, 2011, 01:55:56 PM »

Hello,

im new here and have a question to an imac grafics.

i have a 2010 iMac 27" with an ATI 5750 which is MXM 3b

so the question is could i take an 6970m or 6990m and add an efi rom to GPU bios?

would it work?

and would it work with N-Vidia Cards like 560m or 580m?

i think i could solve the overheating problem if i would increase the speed of the fans.     or not?

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diafebus
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« Reply #11 on: January 07, 2012, 09:17:07 PM »

bump!
I just want to ask the same, I own an iMac late 2009 which has ATI radeon HD 4850
I know that 4850 and 5870 are fully compatible, without any problem.
I can't find anybody selling 6970 as separate part... but I wonder if I could by a PC graphic card and install the same EFI used for mac pros to make it work... what do you think?

thanks
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verdf
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:)


« Reply #12 on: January 13, 2012, 06:02:37 PM »

I don't think increasing the speed of the fans would help the problem, rather make it worse.  Undecided
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lion10
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« Reply #13 on: May 12, 2012, 07:22:02 AM »

... so the question is could i take an 6970m or 6990m and add an efi rom to GPU bios? would it work? ...

... but I wonder if I could by a PC graphic card and install the same EFI used for mac pros to make it work... what do you think?

Well, it seems that this will NOT work so easy. As Rominator mentioned, PC MXM (often) has smaller capacity EEPROM. As a result, the EFI ROM dump will NOT fit. You will brick most likely your MXM card.

I meanwhile bought a bunch of original MXM Geforce 7300GT cards for a more or less bearable price. That was my "solution" for the 24" iMac Geforce 7600 problem...

However, regarding the ALU iMac line (2007 to 2008) I am really pitted! A replacement in form of an Apple MXM Radeon 2600HD card is between $200 and $300!!! Angry  That's a bad joke!
No person with any comprehension will spent out so much money for so an old MXM card, - especially if a similar PC MXM is available for around $60!

This whole iMac MXM gpu problematic is really an "market gap". Any person with the corresponding skills / technical equipment could make here a good bargain with modified PC MXM cards. Will ask these geeks from Realmacmods (http://www.realmacmods.com/) what they think about that idea.  Wink
« Last Edit: May 12, 2012, 09:09:49 PM by lion10 » Logged
diafebus
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« Reply #14 on: May 12, 2012, 07:09:01 PM »

forget about what I said…
http://www.welovemacs.com/6615969.html

this is working to some iMac 2009 users without any problems Smiley

some day i'll do the upgrade… 550$ for that card is just… too much
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