I understand that processing power was lacking but surely the os of yore must have had much smaller requirements. Also let’s assume we are booting up offline and no updates are indicated. What was Windows doing for 3 – 5 minutes that my android phone manages to zip through in 15 seconds?
In: Technology
Believe it or not, before computers booting up got slow, they were actually really quick, too.
An old DOS machine would boot up in 10 seconds or so. This is because old computers didn’t do much. The command prompt wasn’t a complex interface. There was essentially no software loaded other than a very basic OS, which existed only really to help you run software, one program at a time.
When we got to OSes with GUIs, multitasking, and more, we started loading every program and bit of functionality while booting up, but the hardware of the era was a lot slower – specifically hard disks.
These days, OSes have been optimized to only load necessary functions at first and then gradually load other applications and background processes.
The reason old “spinning rust” hard drives were so slow is because there would be a literal platter that spins, and if you wanted some data from it, a head would need to move and then it would need to wait for the platter to spin to the point where the data started. While there is no needle involved, imagine that a hard drive works more like a record player with a “smart” needle.
The most common HDD speeds were 5400RPM and 7200RPM. There were some 4000RPM drives and slower, and there were some 10k RPM drives too (loud and expensive!), but a normal midrange desktop PC would have a 5400RPM hard drive.
The data transfer rates of HDDs wasn’t bad for single continuous files, but for a lot of small files, the heads on the HDD would need to zip back and forth, while spending a lot of time waiting for the platter to spin around too. The data could become fragmented, too, where rather than one file being a continuous stream of data, it would need to be scattered over the whole drive in different places. This slowed down file transfers even more.
A common HDD performance benchmark was “access time” – how long it would take the hard drive to access the data when you request it. For a typical HDD, you might have an access time of approximately 12ms – that would be 0.012 seconds. That sounds extremely fast, right? Well, that equates to a maximum number of different tiny files to about 90 per second.
That sounds very fast in human terms, but in computer terms, it is glacially slow. If you’re booting up the computer, it accesses thousands of tiny files. If we abstract the full booting process to, say, access 4,000 tiny files, it would take that hard drive 44.4 seconds to get to them all.
SSDs are solid state – you’re not waiting on a platter to spin, so they work more or less at the speed of other electronic systems – they’re still an order of magnitude slower than RAM as the reading and particularly writing process is slower, but they are an order of magnitude faster than a hard drive, too. Not only that, many SSDs come with RAM on them to speed data transfers and such even more!
Whereas the HDD needs to operate sequentially and has to wait on a physical platter, the SSD waits for nothing. If the HDD manages 90 operations per second, the best case scenario for an SSD can look more like 200,000 operations per second. In reality this number will be lower a lot of the time – but even in an SSD “worst case” they can still often handle 15k + operations per second.
What took a HDD 45 seconds to do, the SSD can do in under 1 second. Of course, there are other factors that limit booting speed, so SSDs aren’t 45x faster to boot than HDD systems, but they are the biggest reason that new computers are so much faster. Likewise, with something like a cellphone, they generally don’t have the highest performance storage, but it’s still going to be a LOT quicker than a mechanical hard drive. The data transfer rates of these phones may well be similar to a modern hard drive – for one big file – but for things like booting phones up, loading software, and such, solid state will beat mechanical storage every time.
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