For those that didn't read the posts in the news page and 6800 feedback page earlier this year when the Mac 6800 Ultra's first shipped, there were a lot of complaints on fan noise. With my 2003 G5 (w/fan control firmware update), the 6800ultra's fan wasn't as loud as the other case Fans (based on me stopping the 6800's fan with my finger during stress tests when fan noise was at its highest), but some complained about the 6800's fan as the source of the noise. Nathan was one of the 6800 owners that said their 6800 fan was noisy so I mentioned I had installed Arctic Cooling's NV Silencer 5 on a PC 6800GT and it had a quiet fan plus exhausted hot air out of the case (although not perfect since there's a 1/2in or so air gap between the blower and the PCI vent bracket - see photo below). I wondered at that time if exhausting the air outside the case would reduce the PCI Zone fan speed but later comments from the author of Hardware Monitor (and using it to check duty cycle) showed that bay area temperature isn't the primary factor for that fan. (It runs higher after the fan control update even with the card idle.)
Nathan later wrote he'd bought and installed an NV-5 on his 6800 Ultra and said that it definitely helped with the fan noise. (Note: I assumed Nathan's NV5 kit included a bracket for the Ultra card but he later wrote he used the bracket from his 9600XT. He said he contacted Arctic about the missing Ultra bracket but never got one.) Here's his original mail from Nov. 3rd, 2004:

" I did not have time to write up an article for you but I have finished my testing of the stock cooler and the NV5 Silencer on the NVIDIA 6800 Ultra. It will take some sifting through (he sent folders of pdf files w/hardware monitor tests, but I've not had time to go through those yet.-M), but the results are quite contrary to what most people have been saying about the PCI Zone fan being responsible for the noise increase after the 6800 Ultra's installation. (the fan control firmware update increases the PCI Zone fan speed -see past notes/tests on the 6800 feedback page linked below.-M)
The fan increase does still exist according to the numbers (hardware monitor fan duty cycle reports) but after installing the NV5 Silencer, I hear nothing but silence. The noise increase seems to be coming from the stock NVIDA cooler and not the PCI Zone Fan after all.
Hope this helps!!
Nathan"

Nathan later wrote regarding the bracket for the Ultra card:

" Sorry I just got around to reading the article on my NV5 Silencer install. If you look closely you will notice that I used the bracket off my ATI 9600 XT graphics card. Notice that the right hand DVI output fit through the ADC whole from the ATI card. A little "crustom" but it worked.
Nathan
(I asked if he contact Arctic for a bracket)
My attempts to reach Arctic have been pretty negative. They did say that they would send me a new bracket but it has been almost 3 months and have received nothing. I have attempted to contact them further, but I just get the run around.
Nathan "

A later reader that said his dealer sent the Ultra bracket (for PCs - dual DVI port model) mentioned it didn't fit correctly. (See his 1/28/2005 report below)
The Mac 6800 feedback page has discussions I had with the author of Hardware Monitor on the PCI Zone fan control earlier this fall.

Nathan also sent some photos of the 6800 w/NV-5 installed in his G5. (trimmed/scaled for a web page.)

Note: Although Nathan didn't mention it in the above comments, a reader later wrote that the NV5's fan blocks a 2nd PCI-X slot. (Comments updated)

" ... Yesterday I bought an NV 5 silencer and built it in my computer. It is blocking 2 PCI slots because the fan body on the left side is too high...
Regards, Jochen
(I asked if he'd tried a PCI card to verify it would not fix - i.e. will a short PCI card fit)
As you can see a normal pci card fit. But a pci-x card would not fit. ... So, I have to cut the fan case so a pci-x card would fit. This I will try later because I have no time to do this at the moment."

In the photo above he's removed the NV5 from the 6800 but used the mtg screws on the back of the NV5 to set it to the installed height. (I asked to verify that it's at the same height as when installed on the 6800 card.)

The standard Mac 6800 Ultra (and GT) block one PCI slot as shown in photos in last fall's 6800 Ultra review.

Here's a view of the air gap between the HS/fan's exhaust tube and the PCI vented bracket:

Note: The early model NV5 I bought when they first shipped in August didn't come with a bracket for the Ultra cards (which have dual DVI ports and a 2 PCI slot wide end bracket), which wasn't a problem since I used it on a PC 6800GT (single slot) card, but later packages may or may not have the dual DVI port bracket for Ultra models. (2 readers have said their NV5 kits didn't - if in doubt ask the dealer before buying.) The dual DVI bracket is needed for the Mac 6800GT also (not just the Ultra).

The NV Silencer 5 is a better cooler than the PC 6800GT heatsink, but not really any better than the 6800Ultra's heatsink based on tests in some PC reviews. The Mac 6800GT appears to use the same heatsink as the Ultra, so the main benefit for Mac 6800 owners would be potential for reduced card fan noise and better exhausting of heat outside the case. (Some PC users have also sealed the gap between the blower and the PCI vent bracket.)

The related articles below includes an install guide for an ATI 9800 version of this cooler posted here back in October.

The NV Silencer 5 lists for $33 now, although when they first appeared in the fall I paid rip-egg $50+ for one, at the time nobody else had them. (Pricing Deja-Vu.) www.arctic-cooling.com has a line of Silencer models for various graphics cards.

Other Mac 6800/NV5 Feedback: (latest reports first)

(In reply to the previous post below on low card fan speed)

(added 7/27/2005)
" same fan speed here: 328 RPM (with original 6800 fan.) I tried to change the speed of the fan by running a QuickTime H264 movie in 720p HD resolution and 2 games: GooBall and WarBirds2005 (both in 1024x768 windowed all set to full).

(screenshot scaled down due to size)

As you can see on this screenshot my dual 2.5 was nearly maxed out and the GF6800 graphicprocessor was at 69°C but no change in fan speed - maybe hardwaremonitor does not work correct with that fan?
(either that or the fan control only increases the speed for higher temperatures. The Hardware Monitor screenshot shows 328 UPM (not RPM) - is that german for RPM? I mentioned on the PC the std Nvidia control panel shows 120°C/132°C as the throttle down temp on the GT/Ultra so 69°C relatively speaking isn't that high a temp for this GPU.-M)

Anyway from my personal view there is no use in another fan for the GF6800 Ultra! Some months ago i exchanged the GF6800 Ultra by a fanless GF5200 for some hours to hear the difference. There was no change in overall noise level on my G5 dual 2.5 system.
regards, Mark"

As I mentioned on the 6800 Feedback page and review earlier this year, I never replaced my 6800 Ultra card stock heatsink/fan as it wasn't noisy (the G5's PCI zone fan did run faster with the 6800 installed - Hardware Monitor reports 48.9% duty cycle (even at idle) with the 6800Ultra installed, less with other cards installed), but stopping the card fan temporarily showed it wasn't the source of fan noise.) Some 6800 owners however have said their fan was noisy (at least one noted the blades were contacting something on the heatsink IIRC.)

(added 7/25/2005)
" After reading your site I plucked up the courage to have a go with the Arctic cooler replacement fan on my 6800 (machine is a dual 2.7, the 6800 Ultra is not the original card however as my 9650 had distortion problems and was replaced with the 6800 under warranty - lucky me!)

Anyway, installing the NV5 wasn't difficult, but now Hardware Monitor (3rd party utility - see http://www.bresink.com/osx/HardwareMonitor.html) reports the 6800's fan as a constant 328rpm, which is low.
(When I was running a 6800 in the G5 here I never noticed the card fan speed (maybe I missed it - I was watching the PCI zone fan duty cycle). My Mac 6800Ultra still has the stock heatsink/fan though and I've been using an X800 XT for several months now instead of the 6800.-M)
I was wondering whether other 6800 users have added the NV5 and whether they are experiencing low fan rotations as well.
For the record, today is the hottest day we've had in a couple of years and this room is ~30C (no A/C - it is Scotland after all ;-) and the 6800 temps are fairly static at 60C, but all I'm doing is a bit of light surfing and no intensive stuff. On a regular day, I can hit 70C when gaming (UT 1600x1200xmillions) but it quickly cools down.
(Does the card fan spin higher when you run 3d games for some time? The marine aquarium screensaver/app when run full screen also is a good way to speed up fans - even the PCI zone fan seems to spin up when I run it full screen with most cards, but IIRC with the 6800Ultra it seems to stay pretty constant at 48.9% in my 2003 DP G5, but I've not checked it lately. (Last time I ran the card was using 10.3.x back in January during the X800 XT review comparison tests.)-M)

Should I be concerned that the fan rotation is seemingly 'stuck'? Or perhaps it is designed only to kick in when it's getting even hotter than 70C?
Best wishes, John "

I think I mentioned on the 6800 feedback page here I have a 6800GT card in a PC (windows XP) and the stock nvidia control panel software shows the threshold temperature (the point where the card is downclocked) was listed as 120C (yes, 120C) and the Ultra 6800 threshold was 132C. I saw temps of 80C or so IIRC at times when running some 3d stress tests on the PC. I don't think 70c is a problem.
But I'd expect the card's fan to increase in speed when taxed (but apparently 70C or so isn't high enough to require that - see later report above from a stock 6800 HS/fan user on the same reported RPM.) That's assuming hardware monitor is reading it correctly.

(added 1/28/2005 from 1/26 mail)
"A couple of weeks ago I too installed an NV Silencer, this one involving a 6800 GT on my 2.0 GHz G5. I have to agree with Davor Pasaric that this was not the easiest computer modification I have attempted. It involved removing and replacing more than 15 tiny screws on the video card, and the accompanying directions were not very detailed. In addition, I found it necessary to cut the stock wide 6800 bracket with a pair of tin snips in order to provide an outlet for the fan exhaust to the rear. Yes, I had requested the appropriate single bracket from my Florida Arctic Cooler retail supplier, but the one that was sent did not fit the video card's 2 output jacks. (My butchered modification actually turned out quite well.)

After finishing the installation (about 1.5 hours--I am not an expert), I found the overall fan noise to be about the same. I would agree with Mr. Pasaric that a firmware update allowing a reduction in the PCI bay fan would seem to be the answer. Mr. Bresink's Hardware Monitor shows my video card running nice and cool, with the onboard graphics card fan spinning at 328 RPM; the PCI slot fan, however, runs at 49.8%, which I believe is higher than before installation of the 6800. (It is and the fan runs at a higher duty cycle even with an OEM 9800 Pro card - see my comments on this on the 6800 feedback page.-M)
This leads me to believe that the firmware is still basing PCI fan speed on the video card current draw and not temperature. (this was mentioned last fall on the 6800 feedback page by the author of Hardware Monitor.-M)
For the record I am running Mac OS X 10.3.7 with every software and firmware update as of 1/26/05 installed. I am not unhappy with the Arctic NV Silencer 5, but don't see any reason for a 6800 GT user to install one without some further assistance from Apple. Perhaps a 6800 Ultra owner might experience a reduction in fan noise, but as a GT owner I didn't see much difference.
Bearclaw "

(added 1/21/2005)
"I just installed Arctic Cooling NV5 Silencer in my 2.5 GHz G5. The installation was not easy at all - almost 2 hour job to do it properly. Factory cooler setup is not so easy to disassemble and NV5 cooling plates for memory chips are too high and they need adjustment.
The biggest problem was Apple's rear PCI protection plate on 6800 that in my series is *one* piece for two bays (typical for all Mac 6800 cards including the GT, although the PC 6800GT has a single slot PCI bracket.-M) - unlike on NV5 & 6800 photos on your site.
(My *stock* Mac 6800 Ultra photos do show a single 2 slot wide end bracket as shipped by Apple - however with the NV5 kit you have to change that. *Nathan's* NV5 photos above -do not- show the original Mac 6800 card's end bracket - they show his 6800 w/NV5 cooler installed, which has 2 separate brackets (one vented for the NV5 blower exhaust)
Did your kit not come with replacement brackets? (I mentioned previously here (above) that my early NV5 kit used on a PC GT card didn't ship with a bracket for an Ultra card, but I heard later ones did - and I heard if your NV5 kit did not include an Ultra card bracket to contact them to get one.) I assumed from the photos above that Nathan's NV5 kit included the correct brackets but he later wrote he used the bracket from his 9600XT. He said he contacted Arctic about the missing Ultra bracket but never got one.-M)

So, if you want to put included ventilation plate, you have to cut original part or install the card without it (unsecure as card is not fixed). (I'd never do that - I'd contact Arctic to get the correct bracket for the Ultra card if it's not in the NV5 Kit.-M)

So much about bad news. Good news are that original 6800 fan was the cause of noise and the loudest fan in the system. Now, the system is much quieter and the loudest fan is the one in PCI bay - but that's acceptable level of noise. It didn't slow down even if PCI bay is now colder. After all was it worth it? Yes it was, but now I would like to se firmware update to slow down PCI bay fan.
Thanks for superb site!
Davor Pasaric
Croatia "

I would never want to cut the stock wide bracket - I'd contact Arctic to ask for the correct bracket that you need for an Ultra card (although from a later report even that may need some mods). Nathan said he did some slight mods to a 9600XT bracket. It looks like most kits are still shipping with a single vented bracket - which is all that is needed for the PC 6800GT model (their typical target buyer). But for any (PC or Mac) 6800 Ultra card *and* even for a Mac 6800GT model (since both of the Mac 6800 models have an Ultra heatsink/dual DVI ports) - you need a replacement bracket for the base card (DVI port section) since the stock one is 2 slots wide.

Another Quiet (reportedly) 6800 Cooler Option
(In reply to recent updates here)

I'm planning to order one of these to use on my 6800 Ultra DDL:
Zalman VF700-CU Quiet Copper VGA Cooler
(Update: See this article on a Mac 6800 w/Zalman VF700 Radial Copper heatsink)
Early reviews look very good... cooler and quieter than the Arctic NV5, if some tests I read are to be believed (very little in the way of english reviews so far though - it's just coming out).
Michael F."

For other Mac graphics card related articles, see the Video Topics page.