Re: Hot-rodding my G5 - storage performance
Posted: Wed Aug 23, 2017 2:40 pm
What OS are you going to run on the Talos?
Official Chat Channel: #nekochan // irc.nekochan.net
ClassicHasClass wrote:The endianness matches
ClassicHasClass wrote:To answer both uunix and countzero: yes, it is designed to run Linux, and my unit will be running Linux (probably Debian ppc64le). I would be very surprised if the *BSD guys didn't come up with a port, though, given that the hardware is open stack.
As far as x86 goes, it would be purely software emulation, but QEMU does at least have some dynamic translation capability. The endianness matches, so that's some small improvement.
countzero wrote:ClassicHasClass wrote:The endianness matches
Yup, POWER9 is LE as well as x86, but PowerPC and POWER machines have a special hw instruction which translates a word from BE to LE and LE to BE, and It takes just one clock cycle. It's not a penalty.
ClassicHasClass wrote:I personally prefer big endian because it's how I "think"
Shiunbird wrote:Nowadays I use whichever combo of OS-Application works best for the task in hand. This means I touch three or four OSs daily and store all my data in a FreeNAS box.
But if it is really fast enough, based on your experience, I may get a Talos, retire the G5 and two servers, and hang everything on it, leaving it on 24/7.
I like their products. And they won't be disposable if one day you decommission your G5, because they work with (and are even bootable) with PCs.
ClassicHasClass wrote:The G3 and G4 had a very fast means of automatically treating areas of memory as little endian which was used most notably in VirtualPC, but this is not universal to the PowerPC line (the 604 and the G5 don't have it, for example).
The point is, now you don't have to worry about it, and software should "just work." I personally prefer big endian because it's how I "think" but that battle was lost years ago. And hey, the 6502 is my favourite CPU and it's little endian, so.
johnnym wrote:Do you also plan to test the read/write performance of two M.2 SSDs in PCIe adapters in your G5? All PCIe ports in the Powermac 11,2 models seem to have at least 4 lanes (everymac.com states 2 x PCIe x4, 1 x PCIe x8 and 1 x PCIe x16). So each could theoretically yield 1 GiB/s for reads and 1 GiB/s for writes. And even a single "good" M.2 SSD should outperform SATA SSDs easily. Would be interesting to see, what performance levels your G5 could reach with such SSDs.
Shiunbird wrote:We inherited little endian due to x86's massive success, but I wonder why architectures went little or big endian in the beginning.
Big endian seems to be logical, specially if you are reading memory dumps.
I've always wondered why IBM dropped the feature on the G5.
ClassicHasClass wrote:FWIW, VPC on my Quad runs well enough, but I like the older VPCs, especially on OS 9 where they can just run flat out. VPC 3 I think was the pinnacle for DOS and Win9x gaming.
ClassicHasClass wrote:I've always wondered why IBM dropped the feature on the G5.
The more I work on the metal of the G5, the more it's clear it was a hurry-up job on IBM's part to pacify Apple.