Speed advantage booting/running from SSD?
George T. Greenfield (154) 716 posts |
I’m wondering if my Pi4 will be faster and more responsive if I set it up to boot and run apps from a USB-connected SSD drive rather than the SD card (which is SDXC). RISCOSmark shows a definite read/write speed advantage for the SSD over the SD card, but !Speed gives an advantage to the latter with intermediate block sizes (4, 16, 64Kb) which may be a better reflection of real-world performance. All views and opinions will be gratefully received! |
David J. Ruck (33) 1495 posts |
Try it and see. |
David Pitt (3386) 1248 posts |
Large file transfers are faster on an SSD compared to SD, for example 30MB/s on the SSD as against 20MB/s on an SD. However the ultimate real world test here is a ROM source code untar/bz2 and ROM build where the speed advantage is reversed, 30:20 but in favour of the SD. That is with the best SD I have here, a Silicon Power 32GB no longer on Amazon. SD cards vary a lot. As far as I can see under Raspberry Pi OS there is a very considerable speed up with a USB3 SSD over SD. |
George T. Greenfield (154) 716 posts |
Well, there is that of course, but I was rather hoping for some other viewpoints, based on the users’ experiences. Besides, will my Configure-Boot-Run apps automatically switch from SDFS::HardDisc0.$.Utitilities to SCSI::240GB_SSD.$.Utitilities, or will I need to manually reconstitute them all? |
Stuart Painting (5389) 680 posts |
This is another of those “try it and see” situations. When moving from a Pi3 to a Pi4, I copied everything (!Boot, Apps, Utilities etc.) to a new SSD with a different name: RISC OS picked up all of the “Boot at startup” and “Run at startup” entries first time. However I may have been exceptionally lucky… |
David Pitt (3386) 1248 posts |
Those are all saved with relative file path names of the form The Pinboard can save absolute filenames in |
George T. Greenfield (154) 716 posts |
Well, I’ve gone and taken Druck’s advice, and am now running off the SSD as a Boot drive. Seems smooth, and somewhat faster (i.e., bl**dy fast — Pi4 at 1800Mhz). Thanks to all for the help. All the Configure-Boot-Run stuff translated seamlessly: the key SSD directories were a mirror-image of the SD counterparts. |
David J. Ruck (33) 1495 posts |
That’s great. Trying is the only way to find out, as there is such variability between different SD cards, USB<>SATA cables and SSDs, it’s only possible to vaguely hand wave at what is best. Even when you have benchmarks for specific devices, you can’t really say how maximum transfer rates and random access speeds relate to the mix of files you may be loading in your boot sequence. I always go for the SSD drive for data security, even if the Pi4s much faster SD card interface may be better for random access operations in boot. |
Bryan (8467) 468 posts |
No necessarily. The Pi 4 can hardware boot off USB instead of SD card. |
George T. Greenfield (154) 716 posts |
Wouldn’t that require the reformatting and partitioning of the SSD drive? |
Sprow (202) 1113 posts |
I hope it doesn’t, unless you’re using a pre-2016 vintage Pinboard or there’s some bug in the change to save relative paths (though relative to the !Boot application, so I guess it can save absolute filenames if the files are on a different drive to !Boot). |
David Pitt (3386) 1248 posts |
On closer inspection then the only absolute path of a file on the Boot drive is in Backdrop -S ADFS::Titan4.$.Boot.Wallpaper.Titan.Titanium/jpg Pinning the same file gets it right in the X Pin Boot:^.Boot.Wallpaper.Titan.Titanium/jpg 15 360 Textures are saved relatively using |
David Pitt (3386) 1248 posts |
Custom backdrops will be stored with a relative file path, the fix is in git. Backdrop -S Boot:^.Boot.Wallpaper.Titan.Titanium/jpg Many thanks. |