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One of the best things about GNU/Linux is that it does not always require the latest and greatest hardware in order to work – it performs quite well at times when other operating systems would very simply require a new computer to run their latest versions, or the latest versions of user applications.
So there is a tendency in the community to hold on to hardware for longer periods of time, especially when the owner base may be slightly more computer literate than other sectors of the population. However, as with any technological product, it is to be expected that at some point the law of diminishing returns kicks in, and it becomes simply impractical to run any kind of modern GNU/Linux distribution on a very old computer. Using a computer based on an Intel i386 or i486 to do any real work should probably be considered highly unlikely at this point in time, but, in practice, where should one draw the line between usable and no longer usable hardware? In this piece, I would like to consider a couple of real-world cases that may give the reader some points of reference.
As a first example, let us consider my Acer Extensa 5220 laptop that came out in 2008 and that I acquired new that year. This computer sufficed quite well for my needs at the time, with one GB of RAM, an 80 GB hard drive - with the then-new SATA interface - and Windows Vista. That sets one back a step in time, I suppose. Although I upgraded the RAM to two GBytes at some point, it is clear that some of the technical specifications cannot be belied: RAM must be of the slow DDR2 type since this is all the motherboard will support, the USB 2 ports must remain what they are, and I would be hard pressed to find a suitable replacement for the 802.11g WiFi Card. The processor is a single-threaded Intel Celeron 32-bit CPU running at all of 1700 MHz, and this is not upgradable. However, it still has a fairly nice keyboard, and the screen is fine for my eyes, so it stayed running off and on for the last decade. Even the battery retains about 10 minutes of charge, enough to set off the effects of a sudden power drop.
This computer is running the latest and greatest Linux Mint at the time of writing, version 18.3 Sylvia XFCE (i386) with all applications updated to their latest versions. Aside from Dropbox - which does seem to bog things down a bit with slower hard drives - I have every reason to be satisfied with the computer’s speed. The boot process, from GRUB menu to desktop, takes 126 seconds, Firefox starts up in 10 seconds, and LibreOffice in 7. All this means that if I make some provision for booting (ie, go get my coffee while it does its thing), I can actually use it for some productive work in the fashion it was meant to be used. Even the Firefox and Chrome browsers seem to work relatively well in JavaScript hell, though I do admit to using mostly LibreOffice for text editing on this particular machine.
So, is it still worth my money to upgrade further the existing hardware? At this point, just about the only part that could be swapped for something new would be the hard drive. A rather cheap SSD drive is an obvious candidate. In internal 2.5” form, with a SATA connector, these days they can cost anywhere from about 40€ (35 GPB, 50 USD) new - if one is not too demanding on quality and capacity - to about zero if there is a spare drive lying around in a drawer somewhere. Some of the earlier drives with capacities of 32 or 64 GBytes could very well be doing just that, having been replaced with larger sizes in a production computer somewhere along the line. This is the path I took, with a 32 GByte SSD drive or, more precisely, a 32 GByte m-SATA drive, in card format, placed inside a 2.5” format adapter. I connected the new drive to the computer with an external USB-to-SATA interface, formatted it using btrfs and transferred both system and user files over using the btrfs send/receive command. I then reinstalled GRUB on the new drive with the grub-install command using the –boot-directory parameter, and unplugged the usb drive. I then opened up the laptop, and physically swapped the old rotational drive for the new one.
One nice thing about working with this class of computers is that one is not overly concerned about messing things up. The financial implications would be rather low, even if the worst happened. A second point is that access to the computer’s internals is actually quite good for this particular model, as for other laptops of the same time-period. A single cover needs to be removed (held on with 8 Phillips 00 screws), and then RAM, hard drive and WiFi card can all be accessed together. Perhaps this could be a good way of introducing youngsters into the arcane arts of actually working on their devices. But I digress…
Once the hard drive had been swapped, I timed the same actions. Boot from GRUB to desktop was now 103 seconds. So, about a quarter of a minute had been shaved off, but both the limitations of the CPU and of the hard drive’s SATA I bus (just 150 MBytes/s, compared to ATA’s 133 MBytes/s) mean that the speedup is certainly there, but may be seen as marginal as regards actual usability. As for applications, Firefox now started up in 7 seconds, while LibreOffice took a measly 4 seconds. So, while the new values are better than the old, it is clear that the difference is probably not something that could radically alter our current use of this computer.
For this class of machine, I would probably conclude that upgrading some of the hardware would certainly have an educational purpose to it, but that the benefit for practical use of the laptop would at best be marginal.
As a second example, let us take my Acer Aspire One (AO-722) netbook. This one dates from 2011, has an AMD C60 processor with one core but two threads - still at 1600 MHz total frequency, but each thread can take 800 MHz separately - and it is actually a 64-bit machine. The original complement was a 320 GByte rotational hard drive, two GBytes of the slightly faster DDR-3 RAM, and Windows 7 Home Edition. The screen is a 11.7” unit that has its quirks, but still works well. Unlike the Extensa, this netbook does not have an optical unit. Battery life is pretty low after this time, but, with a bit of care, one can eeke out about one hour of power. It currently runs Linux Mint 18.3 Sylvia with the Cinnamon desktop (64-bit). On the positive side for upgraders, access is really easy, with a bottom panel that comes out by unfastening a single Phillips 0 screw.
With the original two Gbytes of RAM and rotational hard drive, boot-up time from GRUB to the (cinnamon) desktop was 65 seconds, launching Firefox took 10 seconds, and LibreOffice 13. This result is interesting in itself. This computer could be expected to be quite a bit faster than the Extensa, by virtue of its superior CPU, faster hard drive connection (SATA-II instead of SATA-I), and faster RAM. While general system boot-up times are coherent with this line of reasoning, Firefox seems to stick to its 10-second times, and LibreOffice is now noticeably slower than before. I am loathe to give a precise explanation for this behavior, but perhaps some of the blame can be placed on using 64-bit versions of this software, which are known for taking up slightly more disk space and RAM than the 32-bit versions used on the Extensa. Other causes related to system libraries may also come into play.
Upgrading the RAM installed to four GBytes gives no speed advantage in the least: 68 seconds to boot the desktop, 10 seconds to launch Firefox and 14 to launch LibreOffice. Within the margin of error of the previous measurements, it is clear that putting more RAM into a computer that is not actually using it (e.g. under heavy use) is not much use at all.
As before, I ended up swapping the rotational hard drive for an SSD, this time a NGFF 32 GByte unit also installed inside an adaptor case to fit into the Aspire’s 2.5” SATA bay. As before, I mounted the new hard drive using an exterior USB cable, formatted it using btrfs, and transferred the system and data snapshots over to the new drive using the btrfs send/receive commands. I then installed GRUB on the new drive, and installed it physically in the computer.
With the new SSD drive, boot time went down to 45 seconds, while Firefox and LibreOffice both launched in 8 seconds. So a noticeable improvement has been seen here, making the drive swap perhaps a worthwhile investment for this class of computer. This bump in speed is actually even more visible when the computer has a more powerful CPU. A Lenovo from a similar time frame (late 2011) boots up in less than 20 seconds, helped no doubt by its then-powerful Intel Core i5 dual core (four-threaded) processor.
Summing up all these factors, my final recommendations would be as follows. In the first place, when working with older 32-bit hardware, a maximum of two GBytes of RAM should be plenty to run most applications. It is also probably not worth the time and hassle to change the hard drive for something faster, since the motherboard will likely not be able to use the supplementary speed. It would be best, to my mind, to simply use lighter distributions such as Xubuntu or Linux Mint XFCE editions, with Linux Mint MATE or Lubuntu as strong alternatives.
On the other hand, once we are speaking of hardware that was formerly of a slightly superior class, such as a 7-to-8 year-old Core i5 or other 64-bit processor, in that case upgrading to a 64-bit version of our favourite distribution will mean that RAM requirements should probably begin at about two GBytes, and move on up from there. Most of these upper tier user-grade or entry-level business-class computers will usually have come with about four GBytes of RAM, which is perfect for most modern GNU/Linux distributions. Naturally, owners with special use-cases, such as video editing, may wish to invest in more RAM - and yes, I have successfully edited quite long videos on my 2011 Lenovo with no difficulties.
In any case, this class of computer will benefit more from a faster hard drive, so upgrading to an SSD model can be seen as a smart move. Besides the clear advantage in speed, it may also be noted that these drives with no moving parts tend to support better use and abuse when on the move, beside requiring less power to work. So changing the drive will usually impact battery life favourably, and make the computer less susceptible to loosing data from hits and falls.
A final reflection I would like to make is that most GNU/Linux developers are definitely in the power-user category. As such, they tend to favour high-end hardware. For this reason, when on the lookout for an older computer to repurpose with any of the variants of Ubuntu or most other mainstream distributions, it may be worthwhile to try and get a more powerful piece of equipment than is really needed. Business-level computers are more likely to be completely supported than some entry-level consumer products. If in the market for a second-hand unit, price differences are no longer quite as noticeable as when buying new, so why not? These computers may also turn out to offer more upgrade paths than lower-end units. An example of this would be my decidedly lower-end Aspire, where one of the RAM slots has never even been solderdered into the motherboard. This would never have been omitted in a power laptop. As usual, though, some precautions need to be taken, such as bringing your bootable USB along when choosing the computer.