Can 4850 iMac owners help find the cause of the freezing? Is it WiFi?

[Poisednoise]

Crashing iMac with wifi, so far no crashes without wifi:

Wireless Card Type: AirPort Extreme (0x14E4, 0x8E)
Wireless Card Locale: Worldwide
Wireless Card Firmware Version: Broadcom BCM43xx 1.0 (5.10.38.27)
Current Wireless Network: AirPort is currently turned off

 

[Topo-kun]

5 HD trailers looping without wifi -> so far 25 min no freezes

2 hours with the 5 HD trailers and no freeze, to go more i do the openGl test at the same time all with spaces active and each thing in one space.

I don't know how valid is this all but for me all the crashes were internet related when I was on wifi.

Perhaps the ATI is affecting the airport card someway.

Anyway, I'm calling support tomorrow, I want a backup plan

EDIT:

Wireless Card Type: AirPort Extreme (0x14E4, 0x8E)
Wireless Card Locale: Worldwide
Wireless Card Firmware Version: Broadcom BCM43xx 1.0 (5.10.38.27)

 

[avihappy]

Wow, I'm pleased with these results! I still want to see people whose iMac are working attempt to use WiFi if they aren't already. Maybe then we can run comparisons on the WiFi chipsets in the ones that work with WiFi and the ones that freeze with WiFi...

So, is there anyone who IS using WiFI (actively connected and begin used), and has no freezes?

Also, is there anyone else who uses Ethernet with WiFi disabled, but still gets freezes? I want to know if anyone has the same issue as fjaekel.

 

[GonzoRob]

and compare them to what? a different model iMac like the 130? 120? 8800? or maybe a different Mac altogether?

It doesn't seem like anyone with the 4850 that hasn't been freezing has been using WiFi so what would be the point of comparing the airport cards unless someone with a non freezing 4850 reports that they have been using WIFI.

I agree

Honestly, nearly everyone uses wifi and I think the freezes are so random that people are clinging onto the hope

Test with wifi (streaming from inet) and GPU stress test going for over an hour - no problems ...

Note: last time i ran this GPU test (2 days ago) the system crashed within 15 minutes.

 

[Tymbo]

Me doing tests too

So far 3 HD(1080p) trailers looping with safari & wifi -> Freezes @ 5 min

5 HD trailers looping without wifi -> so far 25 min no freezes

Trailers running in Quicktime

Configuration 2,93GHz 640 GB

If in an hour I do not become a freeze I would do a Opengl test with the 5 HD trailers running.

I will keep you informed

Kinda sucks how we pay $2k+ to perform tests that apple should have done.

 

[Jammers]

I only use Wi-Fi as I don't have a ethernet cable long enough and I suffer crashes although none for the last three days.

 

[Topo-kun]

Kinda sucks how we pay $2k+ to perform tests that apple should have done.

Agreed, kinda sucks not to know was going on though.

I have a curious mind...

By the way after activating the wifi again and watching some new trailers from apple webpage in HD got another freeze.

 

[GonzoRob]

ok, im going to bed...

windows and wifi card disabled, gpu stress test 2 hours - no crash
windows and wifi card enabled and streaming BBC, stress test 2 hours - no crash.

What's odd is that I do have a freezing imac :/
...guess it didnt want to crash this evening


Also ran prime95 with heavy load for quite a while - no crash.

Im totally stumped. I dont think it's wifi and i dont think its heat...

 

[avihappy]

I only use Wi-Fi as I don't have a ethernet cable long enough and I suffer crashes although none for the last three days.

If these test can confirm that WIFi is the problem, a temporary fix is to buy a wireless bridge, which will connect to the iMac via ethernet and then connect to the network wirelessly.

ok, im going to bed...

windows and wifi card disabled, gpu stress test 2 hours - no crash
windows and wifi card enabled and streaming BBC, stress test 2 hours - no crash.

What's odd is that I do have a freezing imac :/
...guess it didnt want to crash this evening


Also ran prime95 with heavy load for quite a while - no crash.

Im totally stumped. I dont think it's wifi and i dont think its heat...

I don't know if you have entirely falsified the theory. You would need to do a test which reliably causes crashes when WiFi is on (do it twice to be sure), then turn off WiFi and see if the test is able to cause the iMac to crash (use ethernet if the test involves something online).

 

[definitive]

The people on iMacs other than those that have 4850 probably have the same WiFi cards, so I doubt that it's WiFi that's causing this.

 

[arty2shock]

well, i thought about comparing the ATI iMac wifi-Data to the Nvidia iMac wifi-Data.. maybe there's a difference (custom OS or whatever) maybe something else is affecting the ATIs wifi or maybe it's just random sh**^^

it's all about guessing and waiting

 

[Animalk]

The people on iMacs other than those that have 4850 probably have the same WiFi cards, so I doubt that it's WiFi that's causing this.

Two components possibly side-by-side. One may make the environment too hot for the other. The 4850 may be that catalyst.

 

[jebiwan]

As more of you, guys, are posting your experiences turning off and on the wifi of your iMacs I am more convinced that the freezing problem does have nothing to do with the ATI GPU.

The fact that, only the ATI equiped models are failing, may be due to a different chipset on the motherboard of this models, and this chipset may be conflicting with the airport extreme card.

Does anyone knows if the nVidia equiped models have the same chipset than the ATI equiped models?

This is getting interesting. Wifi might be the problem.

As I mentioned in other thread, my iMac hasn't frozen since Saturday, and the only change I made is to tweak my wireless router to manually assign IP to the iMac. I'd suggest people do the same see if your iMac still freezes.

Have you disabled DHCP on your iMac since Saturday or only configured the DHCP server of your router to allways assign the same IP to your iMac?

Remember that it's hard to hang our machines purposely with wifi on, but it's possible and may be what is causing all our headaches.

And it seems to be hardly impossible to hang our machines with wifi completely turned off, this could give us a clue.

 

[aztian]

back up date with my imac

the service told they cant find any problems with it
i ask them what kinda router and keyboard
me at home tuning on whireless network
and blue T keyboard i ask him
do u use the same setup as me with the whireless and keyboard
and he sad no

they only use cabel keyboard and no whireless net work
have u dudes try useing the w/o ? and w/o blue t ?

 

[mstam]

Does anyone knows if the nVidia equiped models have the same chipset than the ATI equiped models?

The chipset on the motherboard will be exactly the same. The video card is connected to the PCIe interface of the South Bridge.

If WiFi seems to cause the lock-ups, it might as well be an interrupt issue or the WiFi card and video card are using the same memory address range. It's most likely the video card causing the issues because people w/ nVidia cards don't experience the lock-ups. A firmware update for the ATI 4850 should fix this.

Kind of sloppy Apple didn't find out about this earlier. I was about to get myself the 24" iMac but will wait till the problem is solved.

 

[aztian]

The chipset on the motherboard will be exactly the same. The video card is connected to the PCIe interface of the South Bridge.

If WiFi seems to cause the lock-ups, it might as well be an interrupt issue or the WiFi card and video card are using the same memory address range. It's most likely the video card causing the issues because people w/ nVidia cards don't experience the lock-ups. A firmware update for the ATI 4850 should fix this.

Kind of sloppy Apple didn't find out about this earlier. I was about to get myself the 24" iMac but will wait till the problem is solved.

well måte we are elite and they are not allways the underground that rocks

 

[GamaFu]

Have you disabled DHCP on your iMac since Saturday or only configured the DHCP server of your router to allways assign the same IP to your iMac?

I configured the DHCP server on router to assign the same IP to the iMac.

 

[ronel129]

I went from experiencing 4 freezes in 2 days to none in the past 2. Three of the 4 freezes were in XP in either chrome playing a flash or in left 4 dead. The single mac OSX lockup was watching a HD video in youtube. These past couple of days i have done everything the same except changing from wifi connection to ethernet and i have experienced 0 lock ups. Is the wifi fixing the lockups for any1 else?

 

[jebiwan]

I went from experiencing 4 freezes in 2 days to none in the past 2. Three of the 4 freezes were in XP in either chrome playing a flash or in left 4 dead. The single mac OSX lockup was watching a HD video in youtube. These past couple of days i have done everything the same except changing from wifi connection to ethernet and i have experienced 0 lock ups. Is the wifi fixing the lockups for any1 else?

Yes, I am in the same situation, my iMac froze 5 times in 2 days since I installed it at home, I disabled wifi 2 days ago and haven't experienced any more freezes.

That's why, despite some people is blaming the ATI card, I still bet that the wifi is very tightly relationed with the problem.

I don't know if the ATI GPU is heating up the wifi chip and therefore causing the failures as some people are saying that installing iMacFanControl and elevating fan speed also solve his problems...

Maybe disabling wifi contributes to keep the iMac a bit cooler and this is why it not freezes any more.

But if it is a heat problem, wouldn't be more easy to lock-up our systems with GPU stressing tests, or playing intense graphic games for hours? And why are there iMacs that freeze 5 minutes after turned on and only
surfing the web?

 

[ineusch]

Could not try the stress test for very long... but I can try again later tonight

Got my iMac yesterday, I do not use WiFi
Under Mac OS X, no problem, done everything I usually do (games, movies, music...)
Under Windows, not problem, played Crysis full res for 2 hours, works great ;D

This morning I enabled the WiFi in Mac OS X, opened 3 HD videos at the same time, opened iTunes with visualizer, left these running for about 20 minutes... no freezing

I ocmpleted the form with this information (forgot my username, my test date is Apr 21 11:16 PM)

Airport info :
AirPort Extreme (0x14E4, 0x8E)
International
Broadcom BCM43xx 1.0 (5.10.38.27)

Any other test I could run to help ? Should I let the first one run longer ?

 

[avihappy]

Could not try the stress test for very long... but I can try again later tonight

Got my iMac yesterday, I do not use WiFi
Under Mac OS X, no problem, done everything I usually do (games, movies, music...)
Under Windows, not problem, played Crysis full res for 2 hours, works great ;D

This morning I enabled the WiFi in Mac OS X, opened 3 HD videos at the same time, opened iTunes with visualizer, left these running for about 20 minutes... no freezing

I ocmpleted the form with this information (forgot my username, my test date is Apr 21 11:16 PM)

Airport info :
AirPort Extreme (0x14E4, 0x8E)
International
Broadcom BCM43xx 1.0 (5.10.38.27)

Any other test I could run to help ? Should I let the first one run longer ?

I would let the "with WiFi" test run longer. You may even want to stream video from HULU and thedailyshow.com (these sites because they stream continuously with AFIAK little buffering). This is where the best possibility for a freeze lies if the WiFi theory is true.

Most people with a freeze say it happens during some kind of internet access. Thanks for the help in testing!

And BTW, you didn't forget to put your username. I added that field after you made your submission.

 

[ineusch]

I would let the "with WiFi" test run longer. You may even want to stream video from HULU and thedailyshow.com (these sites because they stream continuously with AFIAK little buffering). This is where the best possibility for a freeze lies if the WiFi theory is true.

Most people with a freeze say it happens during some kind of internet access. Thanks for the help in testing!

OK, tonight I'll try it again with these
I'll keep you posted

And BTW, you didn't forget to put your username. I added that field after you made your submission.

This explains everything

PS : got a friend on the phone. He has a new Alu MacBook which went back to apple for more or less the exact same symptoms : freezing every 10/15 minutes... after some tests it has been repaired by Apple : the airport card was broken

 

[jebiwan]

Could not try the stress test for very long... but I can try again later tonight

Got my iMac yesterday, I do not use WiFi
Under Mac OS X, no problem, done everything I usually do (games, movies, music...)
Under Windows, not problem, played Crysis full res for 2 hours, works great ;D

This morning I enabled the WiFi in Mac OS X, opened 3 HD videos at the same time, opened iTunes with visualizer, left these running for about 20 minutes... no freezing

I ocmpleted the form with this information (forgot my username, my test date is Apr 21 11:16 PM)

Airport info :
AirPort Extreme (0x14E4, 0x8E)
International
Broadcom BCM43xx 1.0 (5.10.38.27)

Any other test I could run to help ? Should I let the first one run longer ?

Maybe you can post the temperature of the CPU, GPU and all other sensors, after playing Crysis to see if your computer heats up or it remains cold.

Also you can try using only wifi (unplugging ethernet cable) for a couple of days to see if you experience any lock-up.

Maybe you are the one that proves that there are models without any problem. And then, I can call Apple to replace mine

 

[palantas]

After having had more than 10+ freezes since I received my Imac 4850 7 days ago I have tried to disable the built-in Airport of the Imac. I now only use Ethernet.

I have had 0 freezes in the last 24 hours. I have used powerpoint, Itunes, Safari, streamed youtube HD vids and more.

However I seem to have encountered the other problem mentioned in another thread: the sudden freeze of Bluetooth, so that my wireless mighty Mouse become inactive. I can use my Logitech mouse when this happens, it's also wireless but operates through USB.

So one problem seems solved, atleast for now. I will call Apple tomorrow and enquire if they have heard about this problem. I live in Denmark and the Apple Hotline is in sweden .. I expect they "never ever heard about this problem" when I call them. However I will do it to be sure they make a notice of it, and also to be sure to be entitled to a refund if this problem is indeed Hardware related and not something a firmware update can fix at some point.

 

[cwazytech]

For Non-wifi Users

Is there anyone that connects via ethernet(wifi off) that are experiencing freezes?

It seems like the only one answering are wifi users and no offense, but I don't want you to answer please.