Uhhhhh...X1600 in iMac horribly underclocked?

[Vlade]

Yes. The speed settings are saved in the ROM. If you fry the card and take it in for repair a technician could read the ROM, find your overclock setting in there and tell you to get lost.

Of course, you could always change it back to stock numbers before taking it in for repair, assuming the computer is still usable. But OC'ing to failure DOES void your Applecare, and Apple MAY be able to tell, or at least be suspicious enough to give you a hard time.

No, where does it say it writes anything to ROM, because it doesn't, only if you flash the card..... This guy is correct -

The speed settings are not save in rom. The ATItool must be relaunched if you shut down windows to reestablish the clock speeds.

Glor

Thats the way it always is with PC Video cards, and because everything is software and there is no writing to the ROM there is no 100% proof that a card was OCed

 

[eva01]

I clocked mine at 500/540 imac 20" X1600 256mb

HalfLife 2 Lost Coast Stress Test

54 Average FPS at 1680x1080 Everything on High, with HDR on Bloom Only. No AA

Without it being clocked same settings..

34 Average FPS..............

Yeah i was happy, i have games autodetect for graphics and now everything auto goes to highest and it works perfectly ^_____^ i am happy brings new life to a card i was going to replace, now to find a raptor HD

 

[Lord Blackadder]

Touche. I was thinking of a flash, since that's what I'm most familiar with.

The ROM does contain the speed settings - the overclocking software merely overrides them.

So in short, yes, OC'ing your GPU does void Applecare, but Apple probably won't be able to prove anything if you need a logic boar replaced.

I'm not trying to spoil the fun, just trying to inject some caution. Just because Apple can't prove you OC'd you card to death doesn't mean it will be fun getting your logic board replaced if it goes down.

 

[Hotwng]

Intel iMacs videocards are underclocked

A user under the name Alexander here on the Mac Rumors forums (Windows on Mac section) realized that his low-end 17inch iMac's videocard was running at 313 Mhz core, 300 Mhz memory. He checked and found that it SHOULD be running at 470Mhz for the X1600 mobility according to official ATi's specs. So what did he do? He overclocked it by 50%, resulting in a 50% increase in framerates. He got it to run at 440Mhz core and 576Mhz memory while it being still stable.

He compared Guild Wars before and after.

Before overclocking: 30 fps
After overclocking: 47 fps


Another user under the name MacRumorUser also tried overclocking, this time with the 20 inch iMac. This is his results:

Overclocked to 500/540 iMac 20" X1600 256MB, using the Halflife 2 Lost Coast Stress Test as the benchmark. Default is 400/400.

Before overclocking, 1680x1080 settings maxed with HDR on Bloom Only. No AA. 34 fps

AFTER overclocking to 500/540, 54 fps.

To overclock, download this program (its WINDOWS ONLY). ATi Tool 0.25 Beta 14. Lets see some results! Start low and work your way up, if you start to see artifacts (weird things on your screen) lower the clock speed. Remember, these cards are underclocked so you should be able to overclock, increasing performance in games. Your results may vary.

Link to thread

[Moderator note: thread merged]

 

[OutThere]

I'm gonna assume that they have a reason for underclocking the cards, and when people start melting their iMacs, they can cry.

 

[Laslo Panaflex]

iMac 1.83 core Duo, 512mb, X1600 128mb

I clocked the card with ATI tool to 450/450 (the mem and core auto detect crashes).

I ran 3d Mark '03

Standard clocking score: 5006
Overclocking score: 7056

That's a 30% increase in performance, and it could be clocked higher, I was just being safe.

 

[Meemoo]

I am setting my iMac to 500/540 will RAM matter as far as heat goes?

Is there a temp monitor avaliable for windows? the ATI tool for mac crashes control pannel.

 

[biohazard6969]

Is there a temp monitor avaliable for windows? the ATI tool for mac crashes control pannel.

same thing happens with me, i'm guessing its either not universal or doesn't support the X1600, there is no mention of an intel chipset on the site so i don't know

 

[glorfindeal]

same thing happens with me, i'm guessing its either not universal or doesn't support the X1600, there is no mention of an intel chipset on the site so i don't know

I've talked to the developer, it ATIccelerate doesn't support the CD macs at all. He is working on a fix but no luck so far.


Glor

 

[mulletman13]

Woohoo... large performance increase here

 

[harveypooka]

When I run this app it crashes - just locks up. Weird.

 

[biohazard6969]

When I run this app it crashes - just locks up. Weird.

read 3 posts above

 

[Os Xp]

My Problem -
I do the auto-detect-highest thingy and it proceeds well... when I reached about 517 on the core, my screen went black and I couldn't recover it without restarting the whole computer. Any Ideas? (Macbook Pro 2.0 ghz)

 

[eXan]

Hey guys!

Reading through this thread, I wanted to publish my results of overclocking my mobility Radeon 9600 128 MB in my iMac rev. B.

The default clock is 324 MHz Core and 202.5 MHz Memory. (low, eh? )

I increased the clocks by 10 percent each time, gone up to 40 %.

Games, in which I measured the performance are Doom 3 and Unreal Tournament 2004. In Doom I used timedemo cache cammand, 1024x640, High, no shadows, no AA/AF, no VSYNC, everything else ON. In UT I used BridgeOfFate botmatch @ 1440x900 Max settings. BTW it was under 3355 patch.

1) Doom 3

+0 % overclock - 24.2 FPS
+30 % - 30.1 FPS
+40 % - 31.3 FPS

2) UT2004

+0% - 34.7 FPS
+10% - 37.7 FPS
+20% - 39.8 FPS
+30% - 41.4 FPS
+40% - 42.4 FPS.

Note that I increased both core and VRAM speeds simultaneously.

One more test in UT2004 same settings as above, core at the default speed, while memory at 50 % - 37.1 FPS. After running this test and quitting back to OSX artifacts started to show up. Never experimented with overclocking again. Back to default state. Might try later when UT2007 is released

 

[Philberttheduck]

this is annoying. i have the 256 and i can't even touch 450/500. am i doing anything wrong? i set the 450 on core, then slowly increase the memory to 500. then i click SET CLOCK. then the screen blacks out. something wrong? i thought the better the card, the better chances of overclocking.

 

[eXan]

i thought the better the card, the better chances of overclocking.

No, this depends on how much Apple underclocked the cards and something else, maybe cooling. For example Radeon mobility 9600 can be heavily overclocked, while on 9800 you can barely add a few percent and it starts artifacting.

 

[Whiteapple]

It only voids your Applecare if you can't clock it back down! (ie: some idiot with no experience waaaay overclocks it and burns the damn thing up. HINT - if you are getting freezes when playing games, down clock it!)

yes, as long as you bring the clock back down and they dont notice it, then you're clear.
example: on my pc tower, i had set the clocks of my GeForce FX5700 Ultra to about 500-900 cant remember. Then the card blew up, giving me awful display and stuff. Managed to turn it down to normal, still bad display, but then I pickup my phone, call "Point of View" (very good manufacturer btw, 3 years waranty) and now I got a new one for free.

So, shouldnt affect Apple Care for sure if you are a reasonable clock gamer.

 

[MRU]

this is annoying. i have the 256 and i can't even touch 450/500. am i doing anything wrong? i set the 450 on core, then slowly increase the memory to 500. then i click SET CLOCK. then the screen blacks out. something wrong? i thought the better the card, the better chances of overclocking.

Ok I'm confused. What system do you have. Your machine in sig says G5 ???

Please let us know what system you have

 

[Philberttheduck]

my fault.. messed up on the sig. its the 20inch intel. (fixed the sig btw). i actually got it back to 450/500. but playing wc3 tft, the ati-tools message box came up. any suggestions? i do something wrong.

 

[glorfindeal]

my fault.. messed up on the sig. its the 20inch intel. (fixed the sig btw). i actually got it back to 450/500. but playing wc3 tft, the ati-tools message box came up. any suggestions? i do something wrong.

Sorry, but not all chips are equal. You probably got one that can't be clocked up as much.


Glor

 

[MRU]

Yeah that sucks. Maybe there was a reason Apple underclocked them, to make the peformace standard.

After all they are using a dodgy 1.67 duo core with 1 disabled/broken core clocked at a slower 1.5 in the mac mini. So it's not unfeasable for them to use slightly dubios x1600 that havent passed the desktop clock speeds and clock them lower.....

 

[Temujin]

Yes. The speed settings are saved in the ROM. If you fry the card and take it in for repair a technician could read the ROM, find your overclock setting in there and tell you to get lost.

ROM = Read Only Memory

So for this to happen the ROM would be flashed at each OC? Doesnt sound plausible to me.

 

[MRU]

my fault.. messed up on the sig. its the 20inch intel. (fixed the sig btw). i actually got it back to 450/500. but playing wc3 tft, the ati-tools message box came up. any suggestions? i do something wrong.

Ok I got rid of XP, then got a copy of Oblivion, so I put it back in again

Anyway after putting it back in I downloaded ATI Tool again and went back to try and clock it to 500/540 what I had it at before, and it didn't want to know. Kept crapping out on me?

So I tried 450/500 and same thing.

So i wouldnt worry about it too much, seems that the drivers maybe responsible and I'm not sure how accurate then ATI TOOL is reporting. So I have left it as it is...

 

[Xylene]

Yeah that sucks. Maybe there was a reason Apple underclocked them, to make the peformace standard.

After all they are using a dodgy 1.67 duo core with 1 disabled/broken core clocked at a slower 1.5 in the mac mini. So it's not unfeasable for them to use slightly dubios x1600 that havent passed the desktop clock speeds and clock them lower.....

What are you talking about? The processor in the Mac Mini is not a "dodgy" or "defective" Core Dou processor with a disabled core. It's simply a single core version of the same architecture, thus the name, Core Solo.

 

[topicolo]

that's what chipmakers do. If they're making dual core chips on the same silicon, they disable the ones that have a defective or faulty core and sell them as single core chips. The same goes for defects that prevent a chip from attaining higher speeds or using more pipelines (in the case of graphics chips). It has been going on for years.