Just to document this:

The ASROCK 939Dual-SATA2 mainboard and the Thermalright SI-120 are
compatible, but just barely. The problem is that the mainboard
does have the right holes, but the original retention module is
not screwed in with a backplate, but mounted with 4 holes and
platic pins. The SI-120 expects to be screwed into a metal backplate
with two screws.

If you want to mount this cooler on this mainboard you either have to
find a K8 metal backplate somewhere or to make one yourself. Screwing
the retention module directly to the mainboard is possible with large
enough washers, but not advisable at all. It seems some Gigabyte
mainboards also need a back plate, I have orderd one and
will post here whether it fits.

Arno

Kai Schaetzl wrote:
> It seems I just hit the same problem. I want to mount a Thermaltake Big
> Typhoon on this Asrock board and was wondering how to remove the retention
> module (which I did and then reapplied it) and where this dreaded back
> plate is supposed to be. If I remove the plastic retention module there's
> "nothing" left. However, there's a second "H Clip" (plus a sponge and
> mylar layer to keep it away from the board) supplied for all non-K8
> installations which obviously fits this purpose. It seems I can just use
> this. But I'm wondering about the requirement of removing the retention
> module. I haven't seen any other retention module yet, but from the
> installation instructions it seems that the module is screwed to the board
> exactly thru the "middle" holes which should be used for mounting the Big
> Typhoon (or SI-120). So, it's obvious you have to remove the module before
> mounting the cooler. But the Asrock module doesn't have any screws there
> because of the four plastic clip mounting. So, I'm wondering if I can
> actually keep the module in place and still install the cooler thru it.
> If I put the CPU in place, stack the cooler on it and the other H-Clip on
> top of that there is still a four millimeter gap between the H-Clip and
> the retention module surface. I can just push the two long screws thru the
> retention module holes and the two H-clips and screw them tight with no
> problem and the retention module still in place it seems!
> The only problem I see is that four millimeter gap. I'd prefer there to be
> no gap at all. If there is a gap there is a chance that I screw one side
> tighter than the other, so that the clip will place more pressure to one
> edge of the CPU than to the other. Do you anticipate the same problem?
> From the installation instructions it looks like I should be using one or
> two of the standoffs to bridge this gap. Though it looks like the standoff
> won't be able to fully bridge the big gap between the board and the
> H-clip. Actually, that gap would remain much wider than it is with the
> retention module still in place. Or did i get something wrong here?
> It seems to me that keeping the retention module in place is preferrable
> to removing it. What do you both think?
> Question to stanmc: What retention module did Thermaltake supply? There's
> none with the typhoon coming (but four standoffs) How did you solve the
> problem of differently tight screwing?
> Thanks!
>
> Kai
>
Kai, I bought a Thermalright not a Thermaltake heatsink. It came with an
RM, but not a backplate. Thermalright offers a backplate for K8
installations. It is metal with an insulating layer. After you pull the
pins on the AsRock RM you attach the Thermalright backplate and then
place the Thermalright RM in place on the other side of the board and
use the supplied screws to attach it. The SI-120 clips/snaps into the
Thermalright RM.

As for the Big Typhoon I see several clips which I suppose go on both
sides of the board. I don't know how the clips are intended to be
attached and can't find an install guide on the Thermaltake site. I did
find this review of the Big Typhoon with some mention of the
installation of the unit. I think they do intend for you to place one of
the K8 clips on the bottom and one over the heatsink and screw them
together.

http://www.lanaddict.com/rev/159/1/

The installation comments begin on page 2. Best wishes.

Previously stanmc <(E-Mail Removed)> wrote:
> Arno Wagner wrote:
>> Just to document this:
>>
>> The ASROCK 939Dual-SATA2 mainboard and the Thermalright SI-120 are
>> compatible, but just barely. The problem is that the mainboard
>> does have the right holes, but the original retention module is
>> not screwed in with a backplate, but mounted with 4 holes and
>> platic pins. The SI-120 expects to be screwed into a metal backplate
>> with two screws.
>>
>> If you want to mount this cooler on this mainboard you either have to
>> find a K8 metal backplate somewhere or to make one yourself. Screwing
>> the retention module directly to the mainboard is possible with large
>> enough washers, but not advisable at all. It seems some Gigabyte
>> mainboards also need a back plate, I have orderd one and
>> will post here whether it fits.
>>
>> Arno
>>
>>
>>
> Built this same combination a few months ago. Ordered the backplate that
> works with the XP-120 from the dealer and it install perfectly. The
> Instructions for the SI-120 said I had to use nail polish remover to
> loosen the original retention module from the motherboard, but in the
> case of the AsRock939 that is not needed. I just unscrewed it, put the
> Thermalright supplied RM in place and screwed it to the metal backplate.
> Worked perfectly.

I got my backplate today and can confirm this. It seems the backplate
is standardised by AMD in the CPU cooling guidelines, so any generic
k8 backplate should work. The holes are standardised as well, ASROK
just added four more for their own retention module.

> AsRock939 Dual Sata2 with Athlon64X2-3800+ 1GB ram and using Fedora Core
> 4 in SMP.

Ha! I was to cheap for that. No SMP here. But I was sorely tempted.

Arno