From owner-freebsd-alpha Mon Aug 9 15:20:25 1999 Delivered-To: freebsd-alpha@freebsd.org Received: from mail2.panix.com (mail2.panix.com [166.84.0.213]) by hub.freebsd.org (Postfix) with ESMTP id 1288014D31 for ; Mon, 9 Aug 1999 15:20:09 -0700 (PDT) (envelope-from tls@panix.com) Received: from panix6.panix.com (panix6.panix.com [166.84.0.231]) by mail2.panix.com (Postfix) with ESMTP id 1174218C38; Mon, 9 Aug 1999 18:17:57 -0400 (EDT) Received: (from tls@localhost) by panix6.panix.com (8.8.8/8.7.1/PanixN1.0) id SAA10605; Mon, 9 Aug 1999 18:17:56 -0400 (EDT) Date: Mon, 9 Aug 1999 18:17:56 -0400 From: Thor Lancelot Simon To: Chuck Robey Cc: alpha@freebsd.org Subject: Re: Installing the heatsink Message-ID: <19990809181756.A10485@rek.tjls.com> Reply-To: tls@rek.tjls.com References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.95.6i In-Reply-To: ; from Chuck Robey on Sat, Jul 31, 1999 at 04:38:22PM -0400 Sender: owner-freebsd-alpha@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Sat, Jul 31, 1999 at 04:38:22PM -0400, Chuck Robey wrote: > My alpha came with a heatsink that has what seems to be a thin lead > gasket, between the processor and the heatsink itself. I've never used > one before; I've always used silicone grease. The gasket is not lead, it is grafoil. If you've handled it with your bare fingers, it's possible that you've damaged it and will need to obtain a new piece -- it is allegedly very susceptible to contamination with skin oils. > Does anyone know if I should use that gasket, and (if so) how should I > think use the silicone grease (if at all)? Is there any rule of thumb > about tightening down those two bolts that connect the heatsink to the > processor? Do *not* use silicone grease. You need to use the correct grafoil gasket, installed without handling with your bare hands (I actually just clean my fingers with isopropyl immediately before handling the gasket, and make sure they're dry, but gloves are a better idea unless you have a large number of surplus alcohol wipes handy :-), and cranked down with *the nuts that came with the heatsink kit* to the correct pressure, using a calibrated-torque driver. If you've done a large number, you can probably get a feel for "the correct pressure", but if not it's best to use the proper tool. This is not unlike installing a head gasket in your car's engine -- if you screw up, you may not find out until something suddenly blows. The Alpha puts out a lot of heat, and that grafoil gasket, installed and compressed properly, gives it a nice uniform path out the top of the processor, with no hot or cold spots. Other methods don't do that, and may lead to sporadic misbehaviour that's nearly impossible to diagnose, once enough time has passed for it to develop. Gasket, heatsink, and nut specifications and torque values are in the thick version of the technical manual for your Alpha motherboard. I can also supply them by email if you don't have or can't get that. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message