On 27 Dec 2020 at 6:42, Jon Brase wrote: > > Dec 27, 2020 12:05:46 AM Frantisek Rysanek > <frantisek.rysa...@post.cz>: > > > On 26 Dec 2020 at 22:40, Jon Brase wrote: > >> > > > 40 MB of RAM in Windows95 - that's something I once had in a > Pentium > > 75 MHz :-) > > Possibly the same model of machine, given that both RAM and CPU > match, and 40 MiB is a rather idiosyncratic amount of RAM (add > opposed to a power of two). Mine's an AST, forget the exact model > number and can't check right now. > No it wasn't the same model. In july 99, I got myself conscripted to have our (then) mandatory military service over with. After a short boot camp, I was assigned to a position in the office of a unit someplace in the countryside - the job involved keeping track of the headcounts, reporting the counts of the three daily meals required to the kitchen, keeping stock of clothing for them and a small ammunition stock. When I arrived, the office had a Compaq desktop with a Pentium 75 and 8 MB of RAM, grinding away at MS Office 6 under Windows 95. And I had two colleagues in the office me who were several months my seniors on the job. And from my first weekend off, I brought back 32 MB of second-hand RAM and was delighted to find out that it worked in the machine. On the next day, my comrades said something like "Frank dunno what you've done to the computer, but it it's blazing fast now." Nine months later, when my time has come to leave the army, I left the RAM in the machine.
> > exceed 25 totally random IOps. Modern 7200rpm desktop SATA > drives > > during the last 15 years can typically achieve some 75 random > IOps. > > About 60 IOps for laptop drives. And those numbers do not grow > > significantly during the years, with new disk drive generations. > > OK, if modern SATA gets 75, then 25 isn't too concerning. I was > worried it might be more like an order of magnitude (or two) > difference. > Um... note that real HDDs have a memory buffer, acting as a write-back cache. Not sure how much RAM the CF cards have, possibly a couple hundred kilobytes. 10-15 years ago, not sure if 2 or 8 MB was the norm in spinning rust. Currently, the basic volume is about 32 MB maybe? , with some higher end PMR drives sporting 64 MB. And then there are SMR drives with 128 or 256 MB of RAM buffer, often called "cache" in the marketing materials, but I suspect that it's more like a working buffer for a single shingled track or segment (sequence of tracks?) that needs to be assembled before writing. Not sure if the whole "shingle buffer" can actually work as a write-back cache. If it could, that would be your perfect "RAM-based swap device, initialized from disk on startup". Just add a SATA/IDE converter. Take a look at the cheapest 2.5" Seagate Barracuda (ST1000LM048 or some such) for instance. Even if the RAM buffer is not enough to cover your whole swap, your modest swap space would likely fit inside the disk drive's "PMR zone", so you possibly wouldn't ever swap into the bulk SMR area which acts like molasses when it comes to tiny random writes. Frank _______________________________________________ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
