Tobias Jachmann sent a photo of his fanless Radeon temperature checked with a cooking thermometer touching the card's heatsink (with the probe through the vents at the rear of the Cube).

I don't know how accurate this thermometer is, but I'd not want to run the card with that high a temperatures shown (74.1 degrees C). I have a fanned Radeon in my Cube and the fan noise is not loud in my opinion (I'd take the fan noise over the very high temperatures reported above any day.) I have a DVM with thermal probe here that's rated for +/- 2 degrees C but the probe is too large a diameter to fit through the vent holes in the rear of the Cube.

(Previous reader comments follow)

" Hi there,
I heard about the latest batch of Cube Radeons where the fan was apparently replaced by a heatsink. I thought I could give it a try and simply ordered one, and in fact, it has the same, TINY heatsink as the Rage128.

It's getting really hot, but so far it works flawlessly. Problem is, there seems to be confusion among Cube owners and even Apple support people if this heatsink was part of a card revision or simply a mistake during assembly.

If they misconfigured it I'd return it immediately, I don't want a card with built-in count down for self-destruction...
Did you hear a definitve answer somewhere?
Steffen
[I told him I had heard of no failures or problems that I remembered and he later replied]

I asked around and found two people who got a fanless Radeon and contacted Apple. That's what they said:

[Note - I have no way to verify these comments are accurate, although I have no reason to doubt it and the comments are verbatim from a reader email, I can't prove that Apple support ever commented the fanless Radeon cards were a mistake.]

According to three different Technical Support supervisors, Arthur (Art) Brough, Giovanni and Robert, the Radeon video card for the Cube is supposed to have a fan. The technical specifications for the card haven't changed. Determining that was the easy part. The difficult part has been getting a repair or replacement for the defective (misconfigured) cards. Yes, that is plural, cards. I have received three cards from the Apple Store, all fanless.

Anyway, I called Alex at Apple Tech Support. He said he would check and see if there was a recent modification to the Cube Radeon to make it fanless. He called me back several times over the next couple days letting me know he was still checking, and four days later he called back saying that there SHOULD be a fan on the Cube Radeon. He called it a part misconfiguration and set me up with the Apple Store to ship them the card back and they will ship me a new one....
Here's the definitive answer that was given to me 3 separate times.

1. Cube Radeons should have a fan. My lead technician confirmed this with the engineers.
2. Someone screwed up and the apple store made/shipped a bunch of them with just heatsinks.
3. These cards are "misconfigured" and may cause heating issues. ....
-Accelerated movies (mpg, mov) have lots of video trash after I've been playing 3D games for a while. AVI has no problem.

Mine gets very hot too. I may have a damaged DIMM chip because of the heat.
[FYI - I'd say it's impossible for a graphics card heatsink to get hot enough to damage the Cube's internals or ram. It should lock up, show video artifacts/screen corruption (the *first sign* of overheating graphics chips), freeze the system, etc. if too hot. I don't see how the Radeon heatsink could get hot enough to damage other components to the point of permanent physical damage in normal use. Long before the ambient temperatures were hot enough to damage other components, you should be seeing major problems with the video output/card to the point where you'd shut down the system or it would freeze. (Just like overclocking, when components get too hot they usually corrupt data, freeze the system, etc..) Unless you left if unattended for a very long periods perhaps, I think you'd see functional problems that forced some action like shutting down/powering off the Cube. Regardless, from the comments here I would not run one of these fanless Radeon cards in my Cube personally. Heat can shorten the life of components, but remember that many are designed to run at high temperatures seen in normal use (try touching the ramdac on a #9 Rev3D card - it would fry an egg and ran for years in a system here.) However it was designed for those temperatures - the issue of small, fanless heatsinks on Radeons used in Cubes is obviously not recommended. -Mike]

That sounded alarming enough to make me remove (and return) the card.

I haven't heard of Cubes that came with a heatsink-Radeon built-in, only of cards that were bought separately. Maybe just the latest/last batch of the retail/AppleStore cards got misconfigured, and those simply didn't get sold enough (yet) to stand out.
Simon "

Fanless Radeon Cube Card Owner Comments: (in reply to this post - latest comments first)
Note: - If I saw anywhere near the temperatures reported by Tobias, I would remove the card. (93C at the heatsink?]

" Hi Mike,
I got my fanless Radeon in early April and called Apple tech support. They said all Cube versions have a fan. Then I called my dealer, he said none of their cube radeons had a fan.

So I thought, well they have just changed it.

The card gets really hot in my cube. I measured 93°C on the heatsink (room temp around 22-25°C) Everything next to the card gets very hot too, especially the RAM modules. [93C is very very hot - I'd expect the video to show corruption if the heatsink was that hot, or the card lock up. If the heatsink was that hot, the internal graphics chip junction temperatures would be even higher, above the ratings of the chip I suspect.-Mike

[Update: He said he was measuring the radeon's heatsink (through the tiny vent holes at the rear vent slice) using a cooking thermometer. I will check my Cube with a digital meter and thermal probe that is rated at +/- 2 degrees C accuracy at up to 100C. However I am using a OEM Radeon card w/Fan. (I tested this tonight, the vent holes over the Radeon are too small for my probe to fit through, so I could only monitor the main CPU heatsink. After 1 hour of browsing and then 1 hour of DVD playback, the (fanned) heatsink (CPU) checked only 46°C. But again this Radeon card has a Fan.)-Mike>]

I haven't had any crashes, or at least I could not tell they were heat related. But the cube seemed more unstable at ambiemt temps higher than 30°C

I expect my cube to fail much much earlier because of that enourmous internal heat. Chips really hate heat, at least a 50% live reduction seems quite possible. [Agreed. If I saw those temperatures I'd not use the card personally.-Mike]

I then tried a small graphic card fan instead of the radeon heatsink (you can pry it off easily)

Added only noise, so I installed a fan in the bottom of the cube (where the factory bracket is). That also added some noise, but lowered the cards temp to 70°C and the G4 runs 5°C lower, now about 37°C.

I don't want my cube to burn out in 2-3 years, so I will try to find the biggest and quietest fan to put in it.
The Rage128 gets around 50°C if I remember it correctly.
greetings
Tobias"

" Mike:
I bought one of the "fanless" Radeon cards for $149.95 from Apple for my G4 Dual 450. I had problems from the beginning, as the pixels on my AppleVision 17" would "dance." I spoke with Apple and they shipped me another card (fanless), and I have the same problem. Then, Apple sent me a new adapter, and that didn't take care of the problem.

When I put the original ATI Rage Pro in, there is no problem.
Co-incidence???

If you have any ideas, let me know.
John N.
P.S. Thanks as always for the best Mac site in the world. "

" Ordered the supposed combo Cube/G4 Radeon card the day before the price dropped. Seems to work fine, although I get lock ups sometimes when loading OpenGL games (most notably 'Alice'). I leave my computer turned on 24/7, so I'm beginning to wonder if overheating is the cause of these lock ups. Provided, however, that I don't do any gaming stuff, it seems to work just fine, and indeed, many games (Oni, Summoner) rarely lock up at all.
--Nik "

(OS 9) OpenGL Games Tip: Since he noted OpenGL games were locking up - remember the tip noted here many times - if you have a system with 256MB or less of ram, with many OpenGL games you need to still enable Virtual Memory (since some games - Alice I think included) want near 150MB of RAM, plus the OS and OpenGL need free RAM. With VM off the OS uses more RAM as do apps.) (This tip does not apply to OS X of course - and remember these are reports from 2001.)

" Hi Mike
I'm not at all concerned about having my purchased, fanless, Radeon get too hot - it sees quite a bit of Quake 3 Arena and the like with no problems. G4 temp software has shown an increase from low 30s operating temp to approx 41 degrees (Centigrade). On one occasion, the cube shut down immediately and without warning - I assume a safety temperature switch. After an hour, it started and ran without a hitch. I moved it to a more open part of my desk, and I've had no problems since. The key for me was clear ventilation to the rear of the cube.

The previous poster is correct - it is the identical heat sink as the Rage 128.
Regards,
Aaron "

I welcome other reports from Cube owners that have a fanless Radeon card (not a modfied one, but a card that shipped with no fan). Send a note (news at xlr8yourmac.com with subject line "Fanless Cube Radeon card") with details and how long you have run the card, as well as the typical use pattern (do you use it for hours on end, extended gameplay, etc. that would tend to heat up the card more than short term or light use.)