They were really slow though. It took minutes to boot up a game from the 1541. I never had one but my friends did, and one of them had a "Fast Load Cartridge", which I believe just replaced the software on the drive and on the computer with better software that was something like 5x as fast.
... which is still significantly slower than the Disk II.
The 1978 Disk II is about 30 times faster than the unaccelerated 1982 Commodore 1540/1541, as well as more reliable,[1] cooler-running,[2] and just more elegantly designed. The same comparison holds for the 4040 and other pre-1541 Commodore drives, albeit with the speed disadvantage vis-a-vis Apple being less.[3]
[1] The 1541's drive head often goes out alignment despite both it and Disk II using similar "ratatatat" methods to return to the first track. Also, the first couple of years of 1541 production were notorious for failures in general.
[2] As the 1541 is a standalone 6502-based computer with an integrated power supply, overheating is constantly an issue.
[3] Yes, the 1541 is slower than earlier Commodore drives, because of the move from parallel to serial IEEE-488 and a hardware bug (that both necessitated and allows for Fast Load and its counterparts)
The bottleneck was with the serial protocol between the drive and C64. It was done via bit banging in software due to some chip bug. The fastloaders replaced the protocol with something more amenable to bitbanging.
It wasn't really the hardware's fault though. It was crippled by Commodore's marketing department wanting to maintain compatibility with the VIC-20's 1540 FDD, which meant that the bit banging method used to work around a bug in the VIA chip had to be used. Then to add insult to injury, because of how the VIC-II and 6510 need to share the bus, it ended up running even slower than the VIC-20.
... which is still significantly slower than the Disk II.
The 1978 Disk II is about 30 times faster than the unaccelerated 1982 Commodore 1540/1541, as well as more reliable,[1] cooler-running,[2] and just more elegantly designed. The same comparison holds for the 4040 and other pre-1541 Commodore drives, albeit with the speed disadvantage vis-a-vis Apple being less.[3]
[1] The 1541's drive head often goes out alignment despite both it and Disk II using similar "ratatatat" methods to return to the first track. Also, the first couple of years of 1541 production were notorious for failures in general.
[2] As the 1541 is a standalone 6502-based computer with an integrated power supply, overheating is constantly an issue.
[3] Yes, the 1541 is slower than earlier Commodore drives, because of the move from parallel to serial IEEE-488 and a hardware bug (that both necessitated and allows for Fast Load and its counterparts)