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Imac Alu gpu: 2600Pro or 2600XT
- Thread starter delville
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Its an XT that has been downclocked.Hi,
Can someone in this forum confirm with 100% certainty that the gpu in the new Imac Alu is a 2600XT and not a 2600Pro?
There is quite a bit of gaming performance gain if it is a 2600XT.
Thank you.
Regards,
Delville
WTF? Why would they do that? Heat? And who is responsible for that? Apple or ATI?
Hi,
Can someone in this forum confirm with 100% certainty that the gpu in the new Imac Alu is a 2600XT and not a 2600Pro?
There is quite a bit of gaming performance gain if it is a 2600XT.
Thank you.
Regards,
Delville
If I remember correctly, in Windows it says the card is an XT. That would seem to suggest the Pro is an underclocked XT. Although XP could be reporting it wrong.
Too bad the iMac doesn't have a 'real' video card though. At least as an option.
Woah, easy there Tiger.
It might be a downclocked XT. Then again, it could also be a tweaked 2600Pro. Only Apple (and ATI) know for certain.
Chip ID says its an Mobility 2600XT. Benchmarks put it somewhere in between a 2600Pro and a 2600XT. I think its fairly safe to say its an underclocked XT (or at least performs like one). The only real difference between a Pro and an XT is the GPU clock and the VRAM (XTs can use GDDR4).
Those who have overclocked it don't get very far before instability sets in. Maybe 10% increase. Not really worth the risk, IMHO.
Yeah I was thinking instability from OC would come into play, given the enclosure.
Yeah, I definitely think the risks outweigh any potential benefits from even a 15% or 20% increase if that were possible. The iMac is a very compact unit and there is a reason Apple clocked the card the way they did.
Still, the games I run (Half-Life 2, Bioshock, Counterstrike: Source, etc) at the native resolution of the 24" display (1900x1200) get very acceptable framerates with medium to high detail settings.
If you're looking for a top-end gaming machine you shouldn't be thinking of an iMac to begin with.
Well, to be honest, there is no high end Mac gaming machine, so it's iMac + 2600 or OS X and nothing.
+1!!
I'd go one step further and say you shouldn't even be looking at a Mac! Granted you can run Windows on a Mac these days, but I think if you want a serious gaming machine you're still better off going with a native Windows machine. Besides, you won't be getting an SLI setup out of an iMac either.
The XT and Pro are probably the same chipset.
The difference is in the maximum stable clock frequency.
(this is probably determined during QC tests, where the chipsets are sorted.)
Apple is probably using XT-rated chipsets/RAM clocked down to a specific frequency that minimizes core temps and ensures stability while still reaching the target performance baseline.
The difference is in the maximum stable clock frequency.
(this is probably determined during QC tests, where the chipsets are sorted.)
Apple is probably using XT-rated chipsets/RAM clocked down to a specific frequency that minimizes core temps and ensures stability while still reaching the target performance baseline.
In Mobility-land there is no Pro chipset, only XT and vanilla. The chip vendor ID for the iMacs is for a Mobility 2600XT (9583). The vanilla Mobility 2600 carries a different vendor ID (http://ati.amd.com/developer/vendorid.html). The ASIC themselves are the same, however. My guess is that Apple wanted to mask the fact that it was using a laptop GPU so it called it a "Pro" seeing as the performance was not unlike a GDDR3 equipped desktop PRO.
From my understanding, it's an underclocked XT (the chip ID confirms it), and apple label it a PRO because people would complain if they knew it was underclocked. If it's called PRO but actually goes a bit faster, people are happy.
As to why it's underclocked, I think it's a combination of power and heat. Heat is obviously a major issue in the space available, but power must be tight too considering that the PSU is built into the same case. Which makes me wonder - would you get better overclocking results if you remove a stick of RAM, or underclock the CPU to draw less power there? Obviously neither would be very good for performance, but it'd be interesting to find out
As to why it's underclocked, I think it's a combination of power and heat. Heat is obviously a major issue in the space available, but power must be tight too considering that the PSU is built into the same case. Which makes me wonder - would you get better overclocking results if you remove a stick of RAM, or underclock the CPU to draw less power there? Obviously neither would be very good for performance, but it'd be interesting to find out
It's a box of cereal
You guys can say anything you want, nobody really knows for sure. Except ATI/Apple.
You guys can say anything you want, nobody really knows for sure. Except ATI/Apple.