OE compile 1,662 packages in 1 day, 16 hours and 15 minutes

Amazing. I posted in December 20, 2022, compiling the packages for the Kirkstone-series in OpenEmbedded, on an Acer Ryzen5 laptop, and it took 4 days and 3 hours to compile 1,620 packages:

https://bkhome.org/news/202212/radical-experiment-to-cool-the-laptop.html

Since then, I replaced the 8GB RAM module with 16GB, giving a total of 24GB, of which about 4GB has to be taken away as it is used by the GPU.
I haven't accurately timed a complete OE build with that extra RAM (and tweak of CPU clock speed and number of cores), but did do a complete recompile and it was a similar time, maybe a little bit quicker.

One of the reasons I bought that laptop was so could just let the OE compile chug away, no matter how long it takes, and my main workhorse PC is free for normal use.

However, after a recent holiday in Brisbane, have been rethinking the strategy. I took that laptop along. It has a 1TB NVME SSD, and I found really didn't have everything I wanted on it.

Another holiday coming soon, about 3 weeks, and this time want to have everything, absolutely everything, on a SSD. All of my projects, especially the OE builds, may require up to 3TB, so I bought a 4TB SSD.

I bought a Samsung 870 EVO 4TB SATA3 SSD and put it into a USB type-c 3.1 gen1 caddy.

Why not buy a NVME SSD? Well, the main reason is that NVME SSDs draw about twice the power of a same-capacity SATA SSD, about 8W versus 4W. A lot of variation on those figures, they are just ball-park approximations. NVME SSDs run hot!

Having a background as an electrical engineer, I am acutely aware of the current limitations of those tiny USB plug/socket contacts. Even though they are rated higher, I do not want to draw more than about 1A. Probably less.
For that reason, I would prefer to stay with a SATA SSD. It's just my thing, feel more comfortable sucking less current out of the USB socket.

My Lenovo Ideacentre desktop PC has two USB type-a 3.1 gen2 sockets. The caddy I have used is only gen1. Gen1 has a data transfer speed of 500MB/sec, whereas gen2 is about 1,000MB/sec (that's bytes, not bits). Now, SATA3 can only do 600MB/sec, and the 870 EVE SSD is claimed to do a bit less than that; sequential read 560MB/sec and sequential write 530MB/sec.

So it would seem that the 3.1 gen1 USB caddy is a good match for the SSD speed. Though, I think that the negotiating between the two will result in a slower throughput. This means that a 3.1 gen2 caddy would probably be better, would allow the SATA3 interface to go full-blast.

However, the local computer parts shop does not stock a 3.1 gen2 caddy. They do have a 3.2 gen2 caddy, which, if memory serves me right, can do about 2,000MB/sec. But, also if memory serves me right, 3.2 must have type-c sockets on both ends. No no, I just checked at Tom's Hardware:

https://www.tomshardware.com/news/usb-3-2-explained

...this has refreshed my memory. gen2, regardless of being 3.1 or 3.2, is 1,000MB/sec. It is gen2x2 that does 2,000MB/sec (and must have usbc-c sockets on both ends).

So, will pop down to the local computer parts shop soon and buy the gen2 caddy. But for now, using the gen1 caddy to do the OE compile. Which brings me to the surprising result as stated in the title of this post...

This new 4TB SSD has a 63MiB fat16 boot partition, about 3.5TiB ext4, and some small ext4 partitions for installing various OSs -- I did that with Gparted. The fat16 partition has the Limine booloader. I have got EasyOS Kirkstone 5.1.1 and Dunfell 4.5.5 installed in the third partition.

To keep this post fairly short, will do a follow-up as to why a complete OE recompile was required. For this post, just reporting on how long it took.

I booted the 4TB SSD on the Lenovo Ideacentre. This has a Intel i3 8th gen CPU and 32GB RAM, and a 62GB swap partition on an internal NVME SSD.

This time, 1,662 packages were compiled, more than before. The build took 1 24-hour day, 16 hours and 15 minutes. Why so much faster? That's incredibly faster!

The build on the laptop was on an internal NVME SSD, and even if it is a budget SSD it is going to be faster than a SATA3 SSD. You would think so, but then, that Samsung 870 EVO has marvelous features. Apart from top-of-the-range speed, for SATA anyway, it also has a long life -- 2,400TBW -- that's the number of terabytes that can be written to it before it dies. I did some maths on that -- you would have to write 1.3TB to it every day for 5 years to kill it. Anyway, I digress; why is the OE build time so quick?

The Lenovo has 32GB RAM, versus 24GB on the laptop. CPU speed would have to be a factor. Then there is RAM bus-width. Anyway, it is good. If I buy a 3.1 gen2 caddy, the build is likely to be even faster. In the past, I have always thought of the USB interface as being a speed-bottleneck, but that is not the case. Now, the limitation is the SATA3 interface.

Ah, there is one other difference. After partitioning the 4TB SSD with Gparted, I disabled the ext4 journal in the 3.5TB partition:

# tune2fs -O ^has_journal /dev/sdb2

...apart from the fact that I am increasingly considering the ext4 journal as unnecessary, the lack of journal is going to reduce writes and reduce compile time. The NVME SSD in the laptop has the journal enabled.

The intention now is to bootup from the 4TB SSD on every computer, not just when on holiday. When at home, will leave it permanently plugged into the Lenovo PC. When away from home, just take the SSD along. No more issues with syncing between different machines, but of course will still have to do backups. That's the plan anyway.    

Tags: easy