Canada Experience

On the parts/details page, I give some part numbers from Fastenal Canada for Canadian readers. One reader attempted to purchase those from Fastenal, but either due to COVID issues or Fastenal’s desire to work only with businesses or something, he was unable to. McMaster either doesn’t ship to Canada or it’d be a real hassle to make that happen (see below). (Edit 9/18/20: another Canadian reader got quoted ~C$120-130 from Fastenal Canada … which seems like way too much)

The solution was for me to order the screws from McMaster and then ship them to Canada. That took approximately forever (~4w start to finish) and was certainly more expensive than it should’ve been (shipping from McMaster to me, and then from me to Canada).

Please comment below if you’d like me to get in touch about how to help work this out if you’re in Canada, or if you’ve found a solution. The only thing I’ve found for McMaster-to-Canada (other than me doing it for you) is (seems to cost $10 plus Canadian shipping, plus McMaster shipping). McMaster will ship to Canada, but it’s a PITA — the buyer needs to be a Canadian business, there’s some customs and border protection issues, etc., etc.

Meanwhile, here’s some photos of a T3600 with a E5-1660 and the dual-fan Noctua NH-U9DX i4 in Canada.


T7600 Upgrade (Reader Submission)

A reader (Nigel Perry) with a T7600 — a dual processor version of the Dell Precision workstations has followed the instructions on this blog and reports that other than needing 2x the parts, the instructions and discussion were spot-on.

In a comment on another post on this blog, he wrote

“The old Dell heat sinks were substantially longer, so it seems like there’s a ton more room in the case now. Also, I noticed the old [Xeon E5-] 2620s would idle around 55 degrees Celsius. These [Xeon E5-2687W] are idling in the mid-30s and I’ve only noticed them as high as mid to high 40s under load.”


Here are some pictures from his install (below). Some things to note:

  • At least one piece needed to be removed from the cover in order to clear the Noctua heatsink.
  • Note that the Noctua heatsinks (silver with grey fan in the middle) are a slightly different shape from the Dell OEM (black), but the Noctua has no trouble clearing the memory (even with the memory cooling air guides installed).
  • There’s an option to attach an additional fan to the Noctua heatsinks. From what I can tell from the pictures, it is unlikely to fit on the front fan, and if installed on the rear fan could yield worse cooling (the output from the front sink would go straight into the input of the additional fan on the rear sink).

If Nigel has anything to add, he should feel free to.

Follow-up Notes

FIRST, I hate to beg, but this is the only place I’ve seen this information … and I can see that lots of people *read* this information, but I only get feedback from a few. Can you just “comment” on this page to say “Hi, thanks”? I’d really appreciate it…

Just a few notes to clarify and elaborate…

  • The “Investigation” page is long and intimidating. Please don’t let that bother you, the instructions on how to install the new heatsink on the Dell motherboard is much more definitive, and described on the “Parts and Links” page. I should’ve titled that page “Parts, Links & Instructions”. Maybe I’ll change that…
  • If you think your Dell Precision is loud before you do this install, you might possibly be disappointed — you may need to run the CPU fan at full speed, all the time. I don’t notice any sound difference, but if you think your computer is loud now, you might be disappointed.
  • The shoulder screw is a “M5 Shoulder Screw”, which means the shoulder is 5mm diameter. The threads on that screw are M4x0.7mm, the link to McMaster-Carr is correct.

Finally, if you post a question/comment and I’m not responsive within ~24h, please post again to bug me. I don’t mean to take a while to answer, but sometimes things fall off my to-do list.


Instructions (including Parts and Links)

In the previous post I described the saga. This post is “just the fact’s ma’am.”


sourcepart number / descriptionqty
(see ASIN if necessary)
AmazonNoctua NH-D9DX i4 3U
(note: includes Noctua heat paste)
Noctua NF-A9 PWM (optional)0 or 1$16.95
5 pin female to 4 pin male PWM
CPU fan cable for Dell
ArctiClean 60ml Kit  (optional)0 or 1$7.67
USMcMaster-CarrPrecision Shoulder Screw
18-8 Stainless Steel
M5x30, M4x0.7 threads
Part# 90278A376
4$4.90 ea
18-8 Stainless Steel Washer
for M5 Screw Size
5.3 mm ID, 10 mm OD
Part # 93475A240
(qty 100)
CAFastenal5mm Shoulder x 30mm Shoulder Length x M4-0.7 Black Oxide Class 12.9 DIN 7379 Alloy Steel Socket Shoulder Bolt
Part #11507180
4C$ <unk>
M5 x 10mm OD DIN 125 A2 Stainless Steel Type A Flat Washer
Part #MW6350000A20000
12C$ <unk>
UPDATE: Of course, if you’re upgrading a dual-processor machine, you’ll need two Noctua heat sinks, eight shoulder screws, and 24 washers.
UPDATE2: In the US, it’s easy to order from McMaster-Carr, but they don’t seem to have a Canadian presence. Fastenal does (, and I’ve noted what I’m pretty sure the correct Fastenal parts are above for Canadian readers — I don’t have prices because I haven’t registered for a Fastenal Canada account, please let me know what their prices are?
UPDATE3: A reader was quoted ~C$100 for the four shoulder screws from Fastenal Canada. That’s too much. Contact me for more information.


sourcepart number / descriptionqty
AmazonPhilips #2 Screwdriver, 4″
Wera 05008720001

(c’mon, you’ve got one of these)
Used to remove stock Dell heat sink
Philips #1 Screwdriver, 3 1/8″
Wera 05008710001

(you may not have one of these)
Used to remove Noctua mounting brackets
2.5 mm Hex Tip T-Handle
Bondhus 15254

Pack of 2
Used to install new heat sink

A note about tools: I’m a firm believer in buying good quality tools, and buying the right tools for the job at hand. Sure, I’ll bet the free screwdriver set that AAA gave you in a little plastic case might be able to get the job done, but it’s more likely to foul screws and cause problems. Wera and Bondhus make excellent tools, and if I was buying tools for this job, this is what I would buy. Others would work well, too. But it’s not worth using the $0.25 screwdriver if you run the risk of fouling up your computer; think of the $30 in tools as $29 of insurance and $1 in tools.


  • Backup your computer; disconnect at least power, but I unplugged everything and carried the computer to a workbench
  • Lay the computer on it’s side (horizontal orientation), remove side cover.
  • With #2 Philips screwdriver, loosen the four screws holding the heat sink down to the motherboard (red circles). It’s best to loosen North & South but not all the way, then East and West all the way, then North all the way, then hold the heat sink with your hand (press down lightly) and then take South all the way out.
  • When the four screws are loose, disconnect the fan cable that goes from the heat sink fan to the motherboard. It’s hard to do this before you remove the heat sink from the CPU. There’s a small latch on the (ref to the image above) right side of the connection to the motherboard which needs to be pressed in a little bit (e.g., with your fingernail) to release. Remove the old heat sink, sell it on eBay (~$25 if you’re lucky).
  • There is (was) thermal paste between the top of the CPU (now exposed) and the heat sink. This needs to be cleaned off the top of the CPU before installing the new heat sink (which involves new thermal paste). I happened to have a set of ArctiClean Thermal Material Remover, but there are alternatives. It’s important to use a lint-free cloth — a paper coffee filter works and it’s the cheapest thing you probably already have that’ll work.
  • Unbox new heat sink, turn it upside-down (screws facing you). Remove the two brackets (each held on by two small screws), bottom right photo shows one screw not yet removed (left) and one screw removed (right). Important: these are Philips #1 screws, you will make a mess if you try to use some other screwdriver.
  • Remove each of the four screws from the two brackets: pull off the plastic retaining clip which holds the screw to the bracket. These pull right off, but I had to grab it with my fingernails as I pulled.
  • Remove the screw (well, it probably fell onto the bench when you pulled the clip off). Put three M5 washers on one of the new shoulder bolts, then the spring, then re-insert into the bracket, and reinstall the retaining clip. Repeat three more times.
  • Reinstall the two brackets. Note that they go in perpendicular to the fan (otherwise they’d interfere with the heat pipes).
  • Clean the mating surface of the heat sink just like you did with the CPU, it’s important that it be very clean for good thermal transfer.
  • Apply a pea-sized dollop of thermal paste in the center of the CPU (the stuff that comes with the new heat sink works pretty well).
  • Extract the fan wiring, it’s probably tucked inside the heat sink. Easier to pull it out now.
  • Similarly, plug the 5-pin-to-4-pin adapter into the motherboard connector now – plenty of room now, less in a moment.
  • One side of the fan indicates the direction it blows; place the heat sink on the CPU oriented such that the fan is blowing toward the back of the case. Be careful to place it straight down, without needing to move it back & forth (you want to keep the thermal paste in the middle of the CPU, and in the middle of the heat sink).
  • Using the 2.5 mm hex T-handle wrench, insert it through one of the holes in the radiator fins through to the new screw on the bottom. Turn the screw a few turns (not all the way), it should require a bit of downward pressure to get started.
  • Repeat on the opposite corner.
  • Repeat on one of the other corners.
  • Repeat on the last corner.
  • Finish tightening one corner down. Do not force it. It should screw in and then affirmatively STOP, don’t go past where it stops.
  • Repeat on the opposite corner.
  • Repeat on one of the other corners
  • Repeat on the last corner.
  • Plug the fan connector into the 5-pin-to-4-adapter.
  • Plug the computer & peripherals in. Turn it on. Watch the fan – it should be turning. If it isn’t (or, as in my case, if it only moved for a moment), the BIOS should complain the CPU fan has failed.
  • If you didn’t have the fan problem, you’re done.

How I Dealt with the Fan Problem

There are four wires that go into the 5-pin connector that plugs into the motherboard. The wire that is next to the empty spot controls the speed of the fan. If you remove that wire, the BIOS can’t slow down the fan, so it runs at full speed. (Shown on the left below, the wire shown in blue, on pin #4.)

It’s easy to remove the wire from the connector. This YouTube video shows how. Or, if you’re feeling bold, a pair of wire cutters will make quick work of it.

Put everything back together and try again. The fan should be spinning at full speed, and it shouldn’t be so loud to be a problem (at least it isn’t for me).

Other Fan Problem-Related Info

First, just to be clear, Noctua’s documentation says that the fans can be run at full speed (as described above) with no trouble at all.

Also, Noctua includes an inline cable which decreases the maximum speed of the fan from 2000 rpm to 1500 rpm. If the noise is an issue for you, you could add this inline and that’d decrease the fan noise. But honestly, these computers have about 6 fans floating around, the Noctua fan on the CPU isn’t going to add much noise.


This post details the investigation I did, and how I managed to get a stock LGA 2011 heat sink installed on my Dell Precision T3600. The next post will lay it all out for you, with part numbers and instructions.


I upgraded the CPU in my Dell Precision T3600 from the stock E5-1607 to an E5-2687W, and found that the idle core temperatures were uncomfortably high (~60C, ~70C under some minor load), and I didn’t have the guts to stress test it like that…

So, Upgrade … Whoops, a Problem

Unfortunately, the Dell motherboard uses a not-very-popular ILM.  The ILM is the mechanical device that holds the CPU against the pins (it’s kind of like what we’d call a socket in the old days).  Typically, they look like this (this is a TE 2134439-2 on the right).

Look carefully at the corners, those raised nubs at each corner are threaded, that’s where the heatsink attaches.  If the T3600 had one of those, it’d be easy – just buy any old thing for the LGA2011 and it’ll pop right on.

But Dell Uses Something Else

But Dell uses an ILM without threaded inserts on the corners for the heatsink; they use something like the TE 2134439-4, which just has holes. As a result, the heatsink screws have nothing to screw into (well, that’s not quite right, Dell’s heatsinks have longer screws, and screw into the motherboard directly.

This guy, faced with this problem, replaced his ILM with a standard one (it turns out that the ILM is really two pieces, one on top of the motherboard, and one on the bottom, and they’re screwed together.  You can (apparently) remove the top part and replace it with a standard part.  But … risky.  Seems like it’d be very easy to foul up the very, very finely pitched spots where the CPU makes contact…

So, in Dell-land, instead of having threaded parts of the ILM, they have a larger diameter hole through the ILM, and the thread the heatsink screws into are part of the motherboard.

If you compare the two heat sinks above (left is an Intel sink, right is a Dell sink), the difference really is how far the screws reach.

I’ve seen a few posts from folks describing what they’ve done to overcome this problem – how they mounted a standard heat sink on a Dell nonstandard ILM:

  • Just Push Harder. Make a standard heat sink work by just compressing the spring a lot and screwing it in. I’d have to be pretty desperate to try this. Some folks have been “successful” and some folks haven’t been.
  • Remove the spring, replace it with several split-ring lock washers (they kind of look like one coil of a spring), stacked to a smaller height than the spring was.
  • Replace the ILM with the standard one. This seems perfectly possible, but rather risky – you’ve got to be real careful with this stuff.

But look, the springs are important, they pull the heat sink down onto the CPU, yielding a nice solid connection for the heat to move into the sink and away from the CPU. Somewhere I saw a spec of 61.92lbf (pounds per foot) spring force. That’s a pretty stiff spring, and it’s a pretty specific pressure. Every LGA2011 heat sink I’ve messed with just barely catches the threads if you push down on the screw when you’re screwing it in. That yields a very specific amount of compression on the spring (4 mm).

Forging Ahead & Heat Sink Choice

I’m not happy with the temperatures the CPU gets up to. So far, it works ok, but I’m worried about long-term failure, and I *do* stress the CPU occasionally which may overheat it. Let’s give it a try.

My replacement heat sink is a Nactua NH-D9DX i4 3U (not an affiliate link), chosen because it’s got good cooling capacity and it doesn’t overhang the ILM (that is, it goes straight up, and the memory that’s next to the ILM won’t cause a clearance issue). This model works for either shape of the standard ILM (“square” or “narrow”), by switching the mounting bracket (see below).

Later, I discovered that in addition to the fan that’s inside of two radiator banks, it’s also possible to mount an (available separately) Noctua fan on the outside of one of the radiators, yielding a two-fan solution.

Because the bracket comes off, I knew I’d be able to put a different screw on. What size screw?

I need an identical screw, but longer exactly as much as the additional distance between the bottom of the mounting bracket and the threaded part of the motherboard (vs. the threaded part of a typical ILM).

Head Diameter8.4 mm
Head Height4 mm
Shoulder Diameter4.92 mm
Shoulder Length23.15 mm
ThreadM4 x 0.7
Thread Length4 mm

Size measurements were taken with a Mitutotoyo caliper, but I’m not a machinist (I just watch them on YouTube).  They’re close enough, really – the thread is right (measured and per a drawing, see below).

How Much Longer Does the Screw Need to Be?

Way up at the top I showed a picture of an ILM and gave the part number.  It turns out that TE Connectivity (the manufacturer of the ILM pictured) makes both the standard ILM and the type that Dell uses (the former is TE part number 2134439-2, the latter 2134439-4).  Helpfully, TE’s product page for these parts has a drawing (page 2 of the PDF).

The drawing shows that the thread for –2 is M4 x 0.7, and the diameter of the hole in –4 (where threads would be in –2) is 5.51mm.

So, what I need is a shoulder screw with M4 x 0.7 threads, and a shoulder that’ll fit through a 5.51mm hole … but how much longer than the Noctua screw?

The drawing to the rescue again!  It shows the distance between the top of the threads on –2 to the bottom of the ILM is 4.2mm, and I’m going to assume that the bottom of the ILM is coplanar with the top of the threaded aspect on the top of the motherboard.


The existing screw has a shoulder length of 23.15mm.  I need a screw with a shoulder length that’s 23.15mm + 4.7mm = 27.85mm.

Hey, guess what?  It’s very unlikely that your local hardware store carries an M5x27.85 shoulder screw.  It’s certain that Home Depot doesn’t.

Find the Darn Screws

Amazon?  Nope.  The local Ace Hardware?  Nope.

I have accounts at a few industrial supply places, so let’s try to see what’s close to 27.85mm.

It turns out that M5x25mm and M5x30mm are standard sizes that generally have a ~8mm head diameter (to hold the top of the spring), and 4 or 5mm M4 x 0.7 threads.  It’s possible that 25mm would be long enough, but maybe not.

Fastenal has a local branch.  M5x25 or M5x30, none in stock.  $7.50, or $11, or $15 ea depending on the metal.

Grainger has a local branch.  M5x25 or M5x30, none in stock.  $5 ea in 18-8 Stainless Steel.

MSC (mail order).  M5x25 or M5x30, about $4 each in 18-8 SS.  Plus shipping.

McMaster-Carr (mail order).  M5x25 or M5x30, about $5 each in 18-8, or more in 316 Stainless Steel.  Custom lengths (minimum quantity = 5, lengths in 0.25mm increments) for about $10 each, but the head diameter (6mm) may not be big enough (recall that the head needs to hold the top of the spring).

McMaster’s shipping rates are better (and their web site is so much easier to deal with).  But at $5 each, I’m not going to buy both the 25 and 30mm sizes.

After the Long Wait for UPS

That was the longest two days in my life. It makes me wish I lived closer to my sisters, who are close enough to drive to McMaster and pick things up will-call. Oh well.

And here we are. On the left is one of the original Noctua screws (& spring), and on the right is the new M5x30 with one M5 washer and spring.

The originals are about 31.15mm total length, the new ones 39mm. This made me question my decision to not also order the M5x25.

Ok, let’s give it a try with two washers (30mm – 27.85mm = 2.15mm, two washers = 2mm).

Well, it’s close.

It fits, but the spring only seems to compress about 2 or 3 mm (comparing the spring length before & after mounting).  I think it’d be better to be closer to the 4 mm thread length. 

The pressure exerted by those springs are important, and every LGA 2011 heat sink I’ve installed has always been set up so it takes a little bit of downward force with the tool for the threads to catch. With just two washers, it didn’t take any force.

Add a washer, and it’s terrific.  A little bit of downward force and the threads catch, the bolts screw fully into the motherboard, the springs compress about 3-4 mm.  Excellent.  Now, take it all apart, clean, heat paste, reinstall.

Warning: The heat sink has holes through the fins above the screws, and you need a long tool to reach through the whole heat sink to turn the screws. For a stock configuration, Noctua provides an L-shaped Allen wrench that fits the heads of the stock screws … which are (oddly) a fractional size (5/32? something). You need a long 2.5 mm hex to install the screws.

Shown: my Snap-on BluePoint 2.5mm T-handle wrench, which is about 6” long. Here’s a non-affiliate Amazon search for 2.5mm T-handle wrenches. If I were you, and had to buy a tool for this, I’d get this one ($8). You’re going to have to apply some downward pressure and the T-handle is helpful for that (and no, I don’t know why Amazon sells the wrench in pairs).

In Situ

After installation, it’s clear that there is plenty of room around the heatsink – distance to the case, the nearby memory, etc., is all perfectly good.

The Fan. OMG, the Fan

I knew that the Dell motherboard CPU Fan connection was nonstandard (they use a 5-pin with 4 pins used connector), but there’s an adaptor cable to connect the Dell motherboard to a standard 4-pin PWM fan. (Amazon, not an affiliate link). Folks have reported success with this cable…

But not me. When I apply power to the PC, the fan moves for a moment, then stops. The BIOS complains of a CPU fan failure. Multimeter & Google searches verify that the adapter is wired correctly.

Some Google searches finds others that had no problem, and others that have the problem I’m seeing. Argh. If you remove the PWM pin from the connector (easily done on the motherboard end of the adapter cable), the fan spins at full speed – not throttled. If noise were an issue for me, that might be a concern.

Someone I found had a similar problem with a PWM fan, and it turns out the fan was bad. At this point, I’m thinking either there’s some marginal compatibility between the Noctua fan and the motherboard, or I got a bad fan.

I fired off an email to Noctua to ask. I also ordered an additional fan… I wasn’t aware before I ordered the heat sink, but it comes with hardware to mount an additional fan (so there’s one in them middle, AND one on one end). If the new fan spins properly, that answers that. And if not, I can either have two unthrottled fans or one, depending on what the CPU temps are and how loud things are.

Cooling Performance

With the stock Dell heat sink, I was seeing idle temperatures near 70C, and 80+C under load.

With the PWM disconnected, and the fan running at 100% (2000 rpm), I’m seeing mid-30C at idle, low 40s C with usage, and ~50C at heavy load (which drops quickly down to 40C again when the load is stopped.)

Yea, that’s a big difference.