Hello all, I’m looking to create a striped Raid with two SSD one being 256gb the other 128gb, same brand and read/write speed though. I have a MacBook Pro mid 2012 with 16gb ram. What’s the easiest way to get this accomplished as the 256gb is already installed in my MacBook and has the latest Catalina update?
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With RAID0 you need two identical sized drives or you will lose out on the storage space of the larger drive. It may also make the creation of the RAID more difficult (assuming macOS will even allow it).
As @MrHoffman points out Apple no longer supports booting from a RAID. While you can still hack together a boot RAID I'm not sure you can do so with Catalina where I think the driver has been completely removed (not sure about Mojave).
A RAID0 is extremely risky as it can easily break. If you do go with RAID0 make sure to have very good backups. I personally would not trust a system with RAID0. I don't think the slight increase in storage access will be worth it under most workloads. You would be much better off purchasing a larger SSD since they don't cost that much these days.
I’d expect the bottleneck here will be the I/O connection Into the RAID-0 stripe set, and would expect that this RAID 0 striping configuration will provide negligible performance benefits for an ~eight year old MacBook Pro. Certainly test it, but I’d suspect this configuration will be throttled by the I/O performance of the external USB or Thunderbolt connection. Might even degrade performance somewhat, as I/O involving the internal SSD will now be limited by external bus speeds. And it means you will always need that second volume present, and if either fails or otherwise gets disconnected, it’s all going to be rolled in from backups.
If this is an external array with multiple devices, yes, stripe them using Disk Utility. I’d still tend to assume that the bottleneck here will still be the I/O path, unless the SSDs here are really slow... That there won’t be an appreciable benefit for most applications. This as an ~eight year old MacBook Pro and its external I/O isn’t the fastest platform for large-scale I/O.
Have at. But I’d doubt most apps and environments will be able to notice a difference between no RAID and RAID-0 with this hardware.
Check the specs. Can your SSDs (already) outrun your SATA? You’re working with 6.0 Gbps Serial ATA (SATA) connections, which many SSDs will outrun. You’re seemingly going to be bus-throttled, and not seek throttled.
Though you are getting a mildly ugly case of wear leveling, with RAID-0. So there’s that.
And AFAIK, RAID-0 boot support is not part of recent macOS versions; with High Sierra and later. You’ll have to hack that together locally, and reportedly also contend with workarounds to install macOS updates.
So essentially I would install the second drive with the adapter, be able to boot from recovery in order to do this since one of the drives is currently installed, and then reinstall OS on the raid array? By all means correct me if I’m wrong. Also, thank you for your reply.
The second ssd will be inserted in the second Sata port inside the machine. The optical drive will have been removed.
An old joke: the 0 in RAID-0 is the number of device failures it can tolerate.
Rinnegan_501 wrote:
Hello all, I’m looking to create a striped Raid with two SSD one being 256gb the other 128gb, same brand and read/write speed though. I have a MacBook Pro mid 2012 with 16gb ram. What’s the easiest way to get this accomplished as the 256gb is already installed in my MacBook and has the latest Catalina update?
Create a disk set using Disk Utility on Mac - Apple Support
macOS Disk Utility Can Create Four Popular RAID Arrays
Looking to create a striped Raid with two SSD one being 256gb the other 128gb
