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

[Headliner]

Im pretty stumped now... Didnt wanna just send my iMac back coz I didnt see the point if there was a chance i was gonna get a crashy one again. Might give it another day or two to see if anything comes up or Apple has any sort of a statement (hahaha... yeaahhhhhh ) and if not I'll get a replacement.

 

[jebiwan]

Hi, I received my 3.06GHz, 4GB RAM, 1TB HD, ATI4850 iMac on friday. I started
using it on saturday and had it freezed about 4 times on saturday and once on sunday very early in the morning just minutes after turning on.

When it freezed, it was not heavily loaded or running intense graphic
applications. In fact on saturday I've played about 40 min. of COD4 with
all graph settings at top level without any problem.

I realized all freezes was always related to something on the net, so I
suspected that could be a problem with WIFI.
I managed to spend from sunday morning until now surfing the web,
downloading huge files, using amule, playing videos from the web and
updating Windows and Ubuntu under VMware Fusion without any freeze.

Can you tell us if you are using your iMac with WIFI or cabled net?

Let's see how fast can we discard this theory...

 

[maverick72]

3.06 ati 4850 1tb

Frozed twice now ... one time in the first 2 minutes of the first boot and the second time friday night while i tried to play a HD quicktime trailer of Fast and Furious 4 (maybe it doesn't like sucky movies?). Got to add that i wasn't doing anything on the imac ... just popped in the room with a friend to show him the imac so it wasn't close to doing something.

Played WoW absolutly all week-end without a single freeze.

Its really weird but it has nothing to do with over heating issue (at least for me anyway).

EDIT:

Just realized after seeing the post with the WIFI theory.... first freeze: downloading updates second freeze: downloading heavy HD trailer... just a tought cause i played wow all WE (not heavy use of wifi but still).

 

[avihappy]

Hi, I received my 3.06GHz, 4GB RAM, 1TB HD, ATI4850 iMac on friday. I started
using it on saturday and had it freezed about 4 times on saturday and once on sunday very early in the morning just minutes after turning on.

When it freezed, it was not heavily loaded or running intense graphic
applications. In fact on saturday I've played about 40 min. of COD4 with
all graph settings at top level without any problem.

I realized all freezes was always related to something on the net, so I
suspected that could be a problem with WIFI.
I managed to spend from sunday morning until now surfing the web,
downloading huge files, using amule, playing videos from the web and
updating Windows and Ubuntu under VMware Fusion without any freeze.

Can you tell us if you are using your iMac with WIFI or cabled net?

Let's see how fast can we discard this theory...

Maybe you should try to use the iMac without any networking at all (turn it all off)? See if that keeps it from crashing. If so, then we may have some guidance on where to look next!

 

[Headliner]

Yeah I think the overheating theory is pretty much debunked now too.. i monitored temps on my imac and there is no correlation at all.

hummmmmmmm

 

[Topo-kun]

For me also the freezes occurred when I was using the wifi.

Two freezes downloading iPhone SDK from Apple developer conection with Safari
(after the first 40 Mb)

One freeze while surfing with Firefox

I have an iMac 2,93 GHz, 640 GB

 

[jebiwan]

I wasn't sure to post my theory of the WIFI until I could do several test with WIFI ON and WIFI OFF. Because of the randomness of the chances to hang the iMac we have to do a lot of tests in order to reproduce the failure.

But I haven't got much time to do the tests so I decided to post the previous to see if you can do some tests, maybe you just only need to activate airport to get a freeze or maybe you have to try to download a 1GByte file to bring off the failure.

 

[jebiwan]

Maybe you should try to use the iMac without any networking at all (turn it all off)? See if that keeps it from crashing. If so, then we may have some guidance on where to look next!

Just turning WIFI off seemed to be enough to keep my iMac from crashing, that's why I think it could be some WIFI problem

 

[davemulheran]

Just a big thanks to all you guys trying to find out the cause of the problem.

I've had my 3.06 ATI since 14 April and it has now frozen about 10 times PLUS!

Im nearing my 14 day return period so I really dont know whether to hang on to it and persits.. or send it back and get a refund!

what would you do!?

 

[maverick72]

Just a big thanks to all you guys trying to find out the cause of the problem.

I've had my 3.06 ATI since 14 April and it has now frozen about 10 times PLUS!

Im nearing my 14 day return period so I really dont know whether to hang on to it and persits.. or send it back and get a refund!

what would you do!?

Best thing you could do right now is turn off wifi and use the ethernet network card. Since you are freezing alot you could add a little something to the wifi bug theory.

 

[jebiwan]

Just a big thanks to all you guys trying to find out the cause of the problem.

I've had my 3.06 ATI since 14 April and it has now frozen about 10 times PLUS!

Im nearing my 14 day return period so I really dont know whether to hang on to it and persits.. or send it back and get a refund!

what would you do!?

I agree with maverick72, maybe you can do a few tests with wifi off to add some statistics. In fact, 14 April is 6 days ago so you are at half of your return period.

Have you called Apple? Do they replace your iMac without problems?

I know it's a total pain in the ass to return our iMacs to Apple but, if 10 days forward I am not totally sure that it is a software problem instead of a hardware issue, then I will call Apple to replace mine.

 

[davemulheran]

I agree with maverick72, maybe you can do a few tests with wifi off to add some statistics. In fact, 14 April is 6 days ago so you are at half of your return period.

Have you called Apple? Do they replace your iMac without problems?

I know it's a total pain in the ass to return our iMacs to Apple but, if 10 days forward I am not totally sure that it is a software problem instead of a hardware issue, then I will call Apple to replace mine.

Thing is, my imac is upstairs and my wireless router is downstairs plugged in to the only phone point in the house. There is no real viable location for me to put the imac and connect to the router buy ethernet, other than the floor and its not going there!

I rang applecare and my local store and notified them of this issue and pointed them towards the forums.

Applecare said I have 14 days to return or after that, they will only 'repair'

Im seriously thinking of returning the ATI and repurchasing a GT130!

 

[GonzoRob]

I'm using this thread to get various data on what may be causing these iMacs to fail.

Theories Tested So Far:

• Memory "MemVendorID" [FALSE, values same in freezing and non freezing iMacs]
• drvincom and SG values [FALSE, it was inconsistent]
• Manufacture Location [TESTING]
• Incorrect CPU fequency in hardware test [Likely FALSE]

Could all iMac owners (including owners of those that work fine) do this test, then fill out this questionaire?

TEST:

• Get your iMac serial number, either from System Profiler or from on the hardware itself.
• Go to http://www.chipmunk.nl/klantenservice/applemodel.html
• Enter your model number and press the button.
• Note down the factory number (for example, W8)
• Also note down the production year, week, and number

Questionaire:


Please, this thread is NOT meant for discussion, so only reply with the questionaire filled out above. Maybe then we can collect some hard data on these iMacs.

Thanks to all who contribute!

Freezing iMac:

Factory: W8 (Shanghai China)
Production year: 2009
Production week: 15 (April)
Production number: 692 (within this week)

also, I dont think the freezing is wifi. My imac froze during setup (migration assistant)

Thing is, my imac is upstairs and my wireless router is downstairs plugged in to the only phone point in the house. There is no real viable location for me to put the imac and connect to the router buy ethernet, other than the floor and its not going there!

I rang applecare and my local store and notified them of this issue and pointed them towards the forums.

Applecare said I have 14 days to return or after that, they will only 'repair'

Im seriously thinking of returning the ATI and repurchasing a GT130!

Dont accept the 'only repair' option. I didn't. They're sending out a new imac asap and getting TNT to call me to arrange a pick up of the old imac. They said I could arrange the pick up for the same day as the drop off - no problems. I guess the imac should be here in 8 days...

 

[jebiwan]

Thing is, my imac is upstairs and my wireless router is downstairs plugged in to the only phone point in the house. There is no real viable location for me to put the imac and connect to the router buy ethernet, other than the floor and its not going there!

I rang applecare and my local store and notified them of this issue and pointed them towards the forums.

Applecare said I have 14 days to return or after that, they will only 'repair'

Im seriously thinking of returning the ATI and repurchasing a GT130!

Maybe you can just turn off wifi and try playing videos and some game for a while to see if it freezes, it's not a very reliable test but I'm trying to prove that I'm wrong because it's more easy than proving that I am right.

I mean, it should be faster to find an iMac that freezes with wifi off than assuming that if my iMac doesn't freeze with wifi turned off then the problem of all iMacs may be the wifi.

Anyway I would do what GonzoRob says. Within 9 days or so I will call Apple for a replacemente if I don't see very clear that the problem is fixed with a software upgrade.

 

[davemulheran]

GonzoRob , PM sent mate

 

[Tom Dahl]

I realized all freezes was always related to something on the net, so I suspected that could be a problem with WIFI.
...
Can you tell us if you are using your iMac with WIFI or cabled net?

In nine days, my iMac has never frozen (playing WoW, image-editing, etc.). I do not use the WiFi capability.

 

[davemulheran]

In nine days, my iMac has never frozen (playing WoW, image-editing, etc.). I do not use the WiFi capability.

Interesting!


unfortunately for me, the whole point of buying my imac was for wireless connectivity in my house!

this is PISS poor from apple! £2K on a top of the range apple computer and I get this cr@p!

EDIT: - I have just rung apple, and they are sending me a replacement and I am to send back the fauly imac when I am ready.

 

[Theraker007]

so far ive had my imac (2.93 w/ 4850) since thursday. I've used it pretty extensively especially the first couple of days especially while downloading and installing various crap.

It has crashed exactly 3 times since thursday:

twice while using itunes and various windows such as safari and adium

the third time i was watching a video on hulu.com

however it has yet to crash while watching a movie on quicktime, burning a dvd, or playing wow, which i imagine where the most intensive processes i've performed so far.

 

[Animalk]

OK, did the hardware test and the clock speed says 3.60GHz. Sorry to disappoint you here.

Something is very wrong with the firmware if this is true. A discrepancy of 600Mhz in any area of the system regarding the processor frequency is a grave problem.

This can lead to some very random behavior where the chip will run momentarily at +600Mhz and overheat itself or any components close by like the bus bridge or the wifi module.

EDIT: Also World of Warcraft is GPU bound. That is the Graphics chip will reach maximum performance way before the cpu. especially in heavily populated areas like Dalaran. So if people are not experiencing crashing in these low fps areas, but they are in very high fps areas, then this would point the blame more towards the processor.

For those who want to run some tests, hit up dalaran at peak hours and see if freezing occurs. then find a nice hidden area where you can stare at a wall and there aren't many players within rendering distance (That means you need to walk for a good minute before you experience any framerate decrease from crowding.)

Also, make sure your framerate is not caped. The command in chat is "/console maxfps _" where _ is your maximum desired framerate. I recommend you try with 99 at first. Once Freezing has been isolated, I recommend you drop the value down to 30. Keep decrementing by 5 fps if freezing still occurs.

good luck.

 

[synagence]

I have been using my working iMac exclusively on ethernet .... i suppose i could try and switch on WiFi and see if i get a lock-up

 

[Sermon]

To add to the WiFi theory - I am NOT using WiFi for my internet connection, I connect via Ethernet and haven't had a single lock-up yet (my iMac arrived on April 14).

 

[jmpage2]

To add to the WiFi theory - I am NOT using WiFi for my internet connection, I connect via Ethernet and haven't had a single lock-up yet (my iMac arrived on April 14).

I doubt Wifi would add extra heat, it could be some sort of interference issue I suppose.

If true this is actually good news for me as I don't plan to use Wi-Fi on mine in the forseeable future.

 

[arty2shock]

i got my iMac today and i'm starting testing if it'll freeze or not
if someone has an idea how to trigger a possible freeze (i'm not playing WoW) please let me know it

Factory: W8 (Shanghai China)code_to_number: 0L2 - W89150L2259

Production year: 2009
Production week: 15 (April)
Production number: 682 (within this week)

 

[MrENGLISH]

i got my iMac today and i'm starting testing if it'll freeze or not
if someone has an idea how to trigger a possible freeze (i'm not playing WoW) please let me know it

Factory: W8 (Shanghai China)code_to_number: 0L2 - W89150L2259

Production year: 2009
Production week: 15 (April)
Production number: 682 (within this week)

Play an HD movie (looped) or play some music with iTunes Visualizer on full screen

 

[jebiwan]

I've tried to reproduce the problem playing four movies at the same time from Safari, and couldn't hang the computer. Then, I was posting my recent tests and it freezed again.

This only proves that it's difficult to hang the iMac purposely.

The only thing I know so far is that my iMac only freezes if I connect to internet via wifi. If I disconnect the wifi, it works perfect for hours. That includes playing games and watching movies so I don't think it is a heat problem.

I don't know if it is a hardware or software problem but I would bet that it is not a heat problem.

By now I bet for the wifi problem until someone tell me otherwise.