In pretty much all my conscious life, people have come to me for advice about buying new computers. Often, they just ignored whatever I said and bought whatever they wanted and then asked whether it was any good. To which I usually said: “Meh… Will do, you still should have listened to me”.
In the last few years, I have seen a certain trend though: People come to me and tell me “I’d like a new laptop, but it shouldn’t cost more than 400€”. Fine, I get it. Many people I know have children now, and they have other priorities. This blog entry here is based upon a late night Facebook-Chat conversation, where I realized how very confusing and hard buying new hardware has become if you aren’t highly informed. You know what? Even in this context, I’m not “highly” informed, just a bit better informed.
First of all, you need to realize that a computer is a complex machine, and it’s the combination of all parts that makes or breaks the performance. In the low-end, there is actually only one part that you can vary and that is the CPU. CPU stands for Central Processing Unit and you can basically call that “the thing that makes calculations”. You might wonder how moving a window on screen is maths, but I assure you: it is. Your computer can only do two things: calculate data and store data. Everything you see and do on your machine is reducible to those two basic actions. The “How” is irrelevant for this discussion.
So, back to my acquaintance. I asked him what type of machine he now has. It’s a Windows Vista-era machine (Still running Vista, I might add), sporting a Intel Core 2 Duo T7500, 2GB RAM and a 320GB Hard disk. Given the information I have, I guessed, it was approximately bought in 2007 as a high-end laptop. I can also tell you immediately that the main bottleneck here will be the 2GB of RAM, but that can easily be fixed with a 40€ upgrade and replacing the hard disk with an 85€ SSD will also give it a boost. Add in a new battery and you might have infused it a bit more life, if it wasn’t for Windows Vista that is only supported until 2017. However, is it actually “worth” upgrading this machine? No. Not if you can buy a decent new machine. Can we buy a decent machine would be the next question…
That’s where a thought process of most people kicks in, that has been indoctrinated by our consumer oriented society: This machine is eight to nine years old, a new one, even a cheaper one must undoubtedly be better. In certain ways, that new machine is going to be better. It will most likely use less electricity and have better battery life, but that’s not why you are replacing your machine, is it? It’s because it’s not doing what you want it to do: it’s too slow for certain tasks. So, given normal peoples workloads, you will want a faster CPU. Let’s take a look at budget PCs. The column called Prozessor means CPU and the one called Speicher means RAM. Ignore the laptops ones tagged “Generalüberholt”, which means “Refurbished”.
First of all, you’ll notice that none of these machines have more than the 4GB RAM, albeit of a higher speed (which is mostly irrelevant, even though one can discuss endlessly about that).
The second thing you notice that many of them have a Celeron N3150 processor. Of course, that doesn’t tell you anything. It might be the best thing since sliced bread. Also, never mind that CPU model numbers are horribly, horribly confusing.
So, how do we compare these CPUs? Well, in honesty, you can’t! Not really. Mostly we use so called “Benchmarks”, which try to evaluate how quick a certain processor does a certain task. Alas, some processor do well on task A, but badly on task B. All benchmarks are pretty much artificial. From my experience the “Passmark CPU benchmark” gives a quite decent indication on what to expect, but it’s no panacea since you need to be able to interpret results. Still, I’m going by this. Let’s look up the scores for the Core 2 Duo T7500 and put them side by side: There you go: gut feeling correct 1522 > 1274, the T7500 is 84% of the speed of the Celeron N3150. It’s faster! Case closed!
Not so fast. First of all, consider this: a low-end budget CPU, just barely beats the old high-end one (The N3150 is a year old, to be fair), which means you’re going to spend 400€ to get just a minimal speed increase? Are you serious? Furthermore, there is a detail that needs to be pointed out. The T7500 has two cores, meaning two independent calculators. The N3150 has four of them. Four is better than two, so, case closed, the N3150 is better!
The thing is: more cores work best in cases where tasks can be split up, and that isn’t true for most tasks. It’s worse: most user-oriented tasks aren’t like that at all. So, the speed of a single core does matter and it matters quite a lot. That’s the line marked “Single Thread Rating”, where you can see for the T7500 that it has a score of 764 versus 418 for the N3150. For so called “single thread tasks” the T7500 is actually better, much better.
My biggest point is: You’re going to spend money for something that is not significantly better. A midrange modern day Core i5 with 8GB RAM (example: Asus ZenBook UX303UA-FN121T ) will set you back the double of your budget, but will triple the performance compared to your old machine and you’ll have double RAM, which also has a positive impact.
Finally, there is one last thing I need to stress. Many people think that computers get slower when they age. I can think of a few scenarios where that is true (defective or dusty fan and a disk slowly getting bad clusters), but as a general rule: Your machine today is as fast as it was when you bought it. What may have changed is the software you are running requires more power. The solution to this is to do an analysis of your needs: What do I need? List it. Identify the software to do that and stick to that software and only that software. It called “having a fixed feature set”, and it generally makes your computing experience more smooth.
If you’re running Windows, and haven’t done that, your machine might be loaded up with all kind of crap over time that you’re actually not using, but still is loaded. The only solution is then to reinstall the machine, which usually requires specialist intervention. (So does the suggested SSD upgrade, by the way.) If you feel adventurous, you might even try using Linux. Talk to your local nerd about it, who might be closer than you think.
If there is one thing you should take away from all of this: Don’t just buy a new computer, because if you do without being properly informed, you might end up with something that isn’t as great as you’d thought it would be. Or as the Romans already said: Caveat Emptor.