www: random/fanless: Limit to 70C; add pSLC drive

Signed-off-by: Alejandro Colomar <alx@kernel.org>

1 files changed, 134 insertions, 121 deletions

diff --git a/srv/www/random/fanless.html b/srv/www/random/fanless.html
index c1e88ce..0c6e870 100644
--- a/srv/www/random/fanless.html
+++ b/srv/www/random/fanless.html
@@ -66,6 +66,12 @@
 		and a few other parts that didn't seem necessary to me.
 		</p>
 		<p>
+		Since I'm not going to use any PCIe cards
+		(that would kill the airflow),
+		I could cut most of the back plate of the case,
+		having better airflow,
+		and also allowing me to manipulate the interior easily.
+		<p>
 		I won't use the USBs in the case (I never trust them),
 		so I cut the USB cables (I couldn't remove them).
 		I removed the cable for the case leds.
@@ -87,8 +93,8 @@
 		Also, I want my computer to last many years,
 		so I can give it away when I stop using it
 		and it will still work for someone else for a long time.
-		This high-end board has great
-		thermal solution and power protection.
+		This high-end board has good quality components,
+		which will hopefully survive many years.
 		</p>
 		<p>
 		I'm not interested in having so many connections.
@@ -107,15 +113,40 @@
 		I might have some component DOA).
 		</p>
 		<p>
-		Finally, a feature I thought I wouldn't be interested in,
+		A feature I thought I wouldn't be interested in,
 		but which I have come to appreciate very much:
-		a 2-digit led screen
-		indicating the CPU temperature at all times after POST
-		(it serves as a debug code during POST).
-		Apart from the usefulness during POST,
-		I'm more interested in the ability to monitor the temps
-		while doing heavy tasks,
-		like compiling a large project.
+		a 2-digit 7-segment display
+		indicating the CPU temperature at all times after POST,
+		which serves as a debug code during POST.
+		However, there's no way to turn off the display only after POST,
+		when I'm no longer interested in monitoring the temps.
+		</p>
+		<p>
+		As always, there's also crap in this board.
+		For some reason motherboard producers
+		believe we want a Christmas tree instead of a computer.
+		This board has two of them;
+		one on top of the I/O,
+		and one on top of the chipset.
+		The one on top of the I/O is removed easily:
+		unscrew the back plate of the board,
+		then the I/O panel.
+		A large plastic panel will come out easily,
+		after you disconnect the cable for the LEDs.
+		For removing the one in the chipset,
+		you'll also need to unscrew the back plate.
+		Then unscrew the M.2 "shield", and the chipset cooler.
+		When you have the cooler separate,
+		you'll need a blade to separate
+		the plastic cover, and a metal one,
+		and then you'll be able to get rid of the screen itself.
+		All of that is glued
+		(and I bet that glue isn't even conducting heat),
+		so it'll be hard to remove,
+		but you can't break the aluminum block,
+		so it should be easy.
+		After you clean all the adhesive,
+		screw it all back again.
 		</p>
 	</li>
 	<li>CPU:
@@ -156,43 +187,25 @@
 		in tasks that I needed to run many years ago,
 		and now I look for the CPUs that have the larger cache,
 		which usually happen to have more cores too.
+		</p>
 		<p>
-		Using 106 W for short periods is fine,
-		but having the led screen showing the temps
-		makes sure you keep an eye to avoid burning the CPU.
-		(I got it to 99 Celsius when
-		compiling the kernel with all cores.
-		Just use less cores if you expect that
-		some heavy task will take more than a couple of minutes.)
-		</p>
-		<p>
-		Here are the temps while compiling a Linux kernel with
-		`make -j8`.
-		I wouldn't do this often,
-		and recommend using only 4 cores for the kernel.
-		For smaller tasks, though,
-		it's fine to use 8 cores, or even all of them.
-		<ul>
-			<li>0 s - 37 °C</li>
-			<li>10 s - 65 °C</li>
-			<li>1 min - 70 °C</li>
-			<li>2 min - 76 °C</li>
-			<li>3 min - 80 °C</li>
-			<li>4 min - 84 °C</li>
-			<li>5 min - 86 °C</li>
-			<li>6 min - 90 °C</li>
-			<li>7 min - 90 °C</li>
-			<li>8 min - 92 °C</li>
-			<li>9 min - 95 °C</li>
-			<li>10 min - 95 °C</li>
-			<li>11 min - 98 °C</li>
-			<li>12 min - 99 °C</li>
-			<li>13 min - 99 °C</li>
-			<li>14 min - 99 °C</li>
-			<li>15 min - 99 °C</li>
-			<li>15:11 - 99 °C (finished)</li>
-			<li>15:15 - 68 °C</li>
-		</ul>
+		In the BIOS,
+		I limited the CPU temperature to 70 °C
+		(the default is 100 °C).
+		The performance drop isn't important,
+		and the lifetime of the motherboard and CPU will increase.
+		For comparison,
+		building a Linux kernel v6.4 with `make -j8`
+		takes 15 minutes with the limiter at 100 °C,
+		and it takes 16:30 with the limiter at 70 °C.
+		</p>
+		<p>
+		Even though only 8 cores are "performance" cores,
+		and the other 16 are "efficiency" ones,
+		they are all useful for performance tasks.
+		Building a kernel with `make -j8` takes 16:30 minutes,
+		and building it with `make -j24` takes 9 minutes
+		(and the computer remains responsive).
 		</p>
 	</li>
 	<li>Cooler:
@@ -212,6 +225,23 @@
 		but it felt too risky.
 		Maybe next time I'll try with a cheaper CPU.
 		</p>
+		<p>
+		You can mount the cooler in 4 positions (every 90°).
+		Of course, the fins shoulg go vertical,
+		which leaves us with only 2 positions:
+		with the fins on top of the left MOSFET heatsink,
+		or with the fins on top of the RAM.
+		I put it to the left,
+		on top of the MOSFET heatsink.
+		That leaves the RAM uncovered,
+		so it's easier to change it if I ever need.
+		Also, in such a low power system,
+		the MOSFETs shouldn't ever be overheating,
+		so I prefer leaving more room for airflow for the RAM sticks.
+		Also, in this position,
+		the CPU cooler is closer to the back of the case,
+		where it'll have better access for fresh air.
+		</p>
 	</li>
 	<li>Thermal pad:
 		<a href="https://www.thermal-grizzly.com/en/products/299-carbonaut-en">Thermal Grizzly Carbonaut</a>
@@ -224,6 +254,11 @@
 		and it's clean and simple.
 		100% recommended.
 		</p>
+		<p>
+		Pastes also have a limited lifetime,
+		and you need to replace them,
+		while pads should live basically forever.
+		</p>
 	</li>
 	<li>GPU: No thanks!
 
@@ -276,10 +311,10 @@
 
 		<p>
 		For the same reasons as with RAM,
-		I restrict myself to the three memory producers.
+		I restrict myself to the three memory producers when possible.
 		</p>
 		<p>
-		In the past, I used Samsung SSDs
+		In the past, I used Samsung SSDs.
 		I have a computer with a 950 Pro,
 		and one with a 960 Pro.
 		They were great drives.
@@ -287,7 +322,7 @@
 		and they were also great.
 		</p>
 		<p>
-		However, in the latest releases,
+		However, in the recent years
 		Samsung has been decreasing the quality of its drives.
 		I don't trust Samsung NVMe drives any more.
 		</p>
@@ -310,9 +345,53 @@
 		It reduces the wear that flowing electrons
 		produces to the NAND flash.
 		(Now I can't find the source, but I read this.)
-		Also, I don't write that much to disk,
+		Also, I don't write that much to disk
 		to get it very hot.
-		It stays around 55~60 °C.
+		It stays around 50~60 °C.
+		</p>
+
+		<a href="https://www.digikey.com/en/products/detail/atp-electronics-inc/AF320GSAJA-8BBIP/16537435">ATP I-Temp NVMe pSLC PCIe Gen3 M.2 2280 SSD N750Pi 320 GB (p/n: AF320GSAJA-8BBIP)</a>
+		<p>
+		For my personal computer,
+		I need around 1 TiB of storage.
+		However, I also built an almost identical computer
+		for my home server.
+		I don't need so much space there,
+		and 100~200 GiB should be enough.
+		What I need here is reliable storage.
+		</p>
+		<p>
+		SLC would be ideal for reliability,
+		but it's too expensive,
+		and is very limited in space.
+		Pseudo-SLC (pSLC) drives have almost the same durability,
+		but are way cheaper,
+		and can use 3D-NAND, so they come in slightly larger sizes.
+		</p>
+		<p>
+		I wanted to use the same M.2 slot in the motherboard,
+		which connects directly to the CPU,
+		for maximum performance,
+		so I needed an M.2 PCIe NVMe drive.
+		This was the only one I found,
+		and it seems it should be faster than the Crucial drive
+		for sustained writes,
+		as there's no cache involved.
+		</p>
+		<p>
+		At 6.4 PB for the TBW (total bytes written),
+		this drive is virtually immortal
+		(if I'd write the entire drive every day
+		--which is not going to happen--,
+		it would last for 54 years).
+		</p>
+		<p>
+		It's only around 6x the price per byte of a Crucial T700,
+		but accounting for the longer lifespan,
+		and faster speed,
+		I'm willing to use it where I don't need 1 TiB.
+		I don't like this trend of packing more bits per cell in SSDs
+		losing speed and durability.
 		</p>
 	</li>
 	<li>PSU:
@@ -320,81 +399,15 @@
 
 		<p>
 		For PSUs, I only trust Seasonic.
-		I've had bad PSUs kill my hardware,
-		so now I only use the best PSUs.
+		Bad PSUs kill hardware.
 		</p>
 		<p>
-		I calculated that I only need around 100~200 W,
+		I calculated that I only need around 150~200 W,
 		so the smallest PSU would work.
-		450 W is the smallest that Seasonic has.
+		450 W is the smallest one that Seasonic has.
 		</p>
 	</li>
 	</ul>
-	<p>
-	That is my main PC,
-	which I'll use every day.
-	Now, I'm planning a similar computer for my server,
-	which currently is on a Raspberry Pi 4B+.
-	</p>
-	<p>
-	The RPi4 is a bit sluggish,
-	and I also fear that longevity is not going to be good,
-	as the cooling is terrible.
-	</p>
-	<p>
-	The RPi4 is a very cheap computer,
-	but if you take into account that it will live a shorter life,
-	and that I need my server to be reliable,
-	a better computer can be worth it.
-	</p>
-	<p>
-	For a server,
-	I plan to use a cheaper CPU,
-	such as the Intel i3-13100T.
-	4 cores are plenty for a personal server,
-	and I don't care about the CPU cache there.
-	Being cheaper, I may dare try delidding it.
-	</p>
-	<p>
-	I also plan to use a different SSD.
-	This time, it'll be a pseudo-SLC one.
-	I don't trust consumer-grade SSDs
-	for something that must be reliable.
-	And HDDs have failed me too.
-	I don't use backups,
-	as everything that I do is on Git.
-	Every one of my computers,
-	where I have the repos cloned,
-	can be considered one of my backups.
-	</p>
-	<p>
-	If one of the computers dies,
-	cloning from my server is trivial.
-	But if my server dies,
-	setting it up again from the clones in my computers
-	is a bit more cumbersome
-	(especially if I'm traveling).
-	So I want it to be more reliable,
-	and thus I want pSLC there.
-	(True SLC would be too expensive.)
-	</p>
-	<p>
-	I also want the drive to be a NVMe M.2 drive,
-	so that I can use it in a MSI z790 ACE without adapters.
-	I would need at least 200 GiB.
-	I found a few drives that have 320 GB
-	and one with 512 GB (maybe GiB?),
-	for slightly over 1 EUR/GB,
-	which seems an acceptable price.
-	</p>
-	<p>
-	Since those drives don't come with a heatsink,
-	I'll probably get one;
-	still don't know which.
-	</p>
-	<p>
-	The other components will likely be the same.
-	</p>
 </div>
 <hr/>
 
@@ -403,7 +416,7 @@
 	<h2><a href="#top">^</a></h2>
 
 	<p>
-	Last modified: <time>Sep/2023</time>
+	Last modified: <time>Oct/2023</time>
 	<br/>
 	<span class="name">Alejandro Colomar</span>
 	</p>