Be clear about which problem you want to address / which metric you want to improve.
Depending on the version you use, RAID can improve HDD throughput either in reads only (RAID 1) or in reads and writes (RAID 0, 5 etc). In case of a slow CPU it can also improve non-I/O performance by offloading. What it will not improve is latency/seek times, so how long it takes between asking for data and that data actually starting to transmit. When you say "snappy", this is the key metric. As a rule of thumb, with mechanical drives, this is determined mostly by rotation speed and platter size. The fastest seek times are seen with the fastest spinning drives, so a 15k rpm drive will - regardless of throughput once the data has been found - run rings around a 5400 or 7200rpm drive. Size also matters - and in this respect is exactly opposite of throughput: the larger your platter, the longer the path given a particular angular movement. So throughput increases but so do seek times. That's why Quantum Bigfoot drives feel so slow and why Velociraptor drives went from 3.5" to 2.5" form factor. Incidentally, this means that a lot of smaller (lower density) platters is better for low seek time whereas one or two huge (high-density) platters is better for linear throughput.
This also means there is no 'perfect' drive. For storage you want a drive with big platters and big linear read/write performance, whereas for OS / swap you want a drive with small, fast platters and generally don't care about linear performance. So your 2010-era dream machine had OS and swap on a tiny Velociraptor with a couple of huge slow-rotating drives in raid for bulk storage. Then came SSDs. They provided incremental increase on linear throughput, but utterly shattered seek times, as there's no physical drive to turn before you can read or write. At a price, a very, very high price at that point.
But you're not looking at a 2010-era dream machine but at a P75 you want to get more snappy. In terms of period-correct stuff, you'd do well to look for the fastest SCSI drive you could find with the highest platter count. It will wail like a banshee, it will get hot as hell but it will beat the pants off an IDE 7200rpm drive with a few big platters. However the noise might prove unbearable and price may be an issue too. You could go for newer SCSI drives, as due to SCSI backwards compatibility, you could stick Seagate Cheetah or Quantum Atlas 10k or 15k drives onto a P75. They are not only a lot faster, but they are acutally pretty quiet too. I have an Atlas IV 10k in my dual P3 box and it's quieter than a generic 7200rpm WD SATA drive. These would also be cheaper/easier to find than a 1995-era drive. Issue would be size: DOS and early WIn95 can't handle partitions over 2GB. Late WIn95 or WIn98 support FAT32 and could handle bigger partitions, but would increase CPU overhead, which would slow the system down in other ways. If you want to/are prepared to abandon period-correct rotational media though there are other options. For my late 486, early Pentium systems, I like to go for IDE (PATA ) Disk-On-Module (DOM) SSDs. You can get 1GB or 2GB modules fairly easily and cheaply. They are physically small, they are silent and they have SSD seek times. CF is also an option, but I find them less reliable over time. Instead I prefer to use CF for data transfer between systems.
One note on SSD, either DOM or CF or SATA with SATA-PATA adaptes: your motherboard has an i430HX chipset with PIIX3 southbridge. It doesn't support UDMA transfers. That will limit throughput a lot vs theoretical abilities of your drive. However it does not affect seek times/latency, so you probably won't notice it - and PCI IDE controllers that do support UDMA open a whole new kettle of fish regarding PCI compatibility and the like.
George Razvan wrote on 2024-02-08, 09:26:
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What about TRIM command for ssd? What will be the speed of the SSD once it would be 100% written to? Woult the lifetime of the SSD be affected ?
Don't fill up your SSDs to 100%. Always keep at least 25% free so the SSD controller can do its job leveling writes. That said, unless you want to use this old machine for work for 40 hours per week, lifetime considerations are completely irrelevant with a modern SSD. With older ones, aim for SLC rather than MLC. I particularly like the Intel X25E series, which are also more manageable in terms of size (32GB or 64GB) - they were exactly the unobtainium I lusted after in 2010.
