Help convince me about SCSI2SD and Flash Storage

[0xABE]

This post could be subtitled: Benefits vs. Risks of Flash Storage, related to SCSI2SD

I am refurbishing a Quadra 660AV with great enthusiasm (our family had a Centris 660AV back in 1993 when they were brand new). Everything currently works, but, just as I am replacing the aluminum caps with new tantalums, I plan on replacing the hard drive and am looking forward to having more storage space than 230MB. I will, however, miss the familiar and comforting click-click-clicking of the HD as the machine sits idle on the desktop.

I have seen Inertial Computing's SCSI2SD solution and think it is clever. However, I have read that flash memory degrades with every write and rewrite. So I am torn. I wonder about the effects of long-term usage on reliability with SCSI2SD. I would consider sticking with a spinning platter of some type although it seems some other adapter is required because 50 pins is an old interface. NewEgg sells 68 and 80 pin SCSI drives.

What are your thoughts regarding the reliability of SCSI2SD and have you installed a new 68/80 pin SCSI in your vintage Mac (and how'd you do it)?

Thanks,

0xABE

 

[maceffects]

I've often worried about the degradation issue so I can't comment on the topic.  I did have some ArtMix SCSI > CF and they never had an issue.  But I do not use them much.  I could never quite figure out how to setup the SCSI2SD to form an opinion on the subject.

 

[uyjulian]

There are high reliability/industrial SD cards available if you are concerned about reliability and endurance.

 

[Byrd]

I've used crappy CF and SD cards in Macs for years, and early SSDs and have never had an issue.  I now use better quality flash storage and try to convert most machines to solid state for performance, ease of use copying files and lower power overheads.  In terms of read/write cycles, you're not going to do enough on a slow SCSI/IDE bus on a vintage Mac to be worried about unless perhaps you have a low memory system with virtual memory on.  If worried?  Backup and get another $10 flash device.

 

[omidimo]

Lower power, less heat, and longer life... all signs point to YES! Panasonic makes great industrial SD/microSDs. Have been running one in a 840AV for 3 years with no problems, and another in Q700 as well. What you lose in sound, you gain with reliability. 

 

[Fizzbinn]

I’ve gone down the 68/80pin scsi disk path and heat ended up being my biggest concern. A lot of these disks (10k/15k rpm) were intended for server use and generate a lot of heat compared to the older, slower rpm 50 pin scsi disks Apple used. Termination can also be a challenge as you need adapters that have high line termination (68 pin disks with on board jumpered termination) or full termination (for 80 pin disks which typically don’t provide any termination). Most of the cheap adapters on eBay don’t have any termination, I found they can work with some drives but introduce SCSI bus problem with external devices.

You can definitely make it work but you need the right adapters and slower rpm drives that generate less heat. I’m pretty happy with a 2.5 inch 10k 80 pin Seagate Savvio disk I have in my Quadra 605, I did put a make shift heat sink on it though... I think I paid ~$50 for the disk and adapter off eBay, a scsi2sd v5 and sd card are somewhere around ~$70. I have a scsi2sd v5 in my IIsi which also works really well, it definitely took me longer to sort out an 80 pin disk for the Quadra then setup the scsi2sd.

 

[0xABE]

I've used crappy CF and SD cards in Macs for years, and early SSDs and have never had an issue.  I now use better quality flash storage and try to convert most machines to solid state for performance, ease of use copying files and lower power overheads.  In terms of read/write cycles, you're not going to do enough on a slow SCSI/IDE bus on a vintage Mac to be worried about unless perhaps you have a low memory system with virtual memory on.  If worried?  Backup and get another $10 flash device.

How did you use the SSD? DataPro taunts me with this page (https://www.datapro.net/products/aztecmonster-ii-scsi-to-sata-adapter.html) but they are out of stock and the rep could only put me on a list for if anything changes in the future.

 

[Byrd]

2.5" SCSI SSDs do exist, but they're frighteningly expensive, very old now and low capacity.

For PowerBooks, look out for the 2.5" SCSI to IDE adapter that Apple put in Powerbook 540s when they needed 1GB+ HDs; I believe they are an ACARD branded part.

For IDE equipped Macs, many of us have used 2.5" or 3.5" IDE to MSATA (or M.2) adapters.  Keep in mind that some later model MSATA SSDs are not fully compliant with the older ATA standards some vintage Macs have, I've only really had good luck with Intel branded MSATA SSDs.

 

[LaPorta]

One way or another, all of these things will eventually die. The way I see it, you should always have a backup of anything that is valuable anyway. Every single classic Mac software /system/thing that I have is backed up on my house server RAID drive, which in turn is backed up bi-yearly to another HD which serves as off-site backup. These old machines aren't usually used the same way new computers are (meaning daily use). I think the amount of time that you use it will probably be so small that if there is any chance of some catastrophic read/write issue, years will have gone by, after which, if you backed up, will not matter since you can just pop in a new SD card and restore from a backup..

Of course, that is just how I see it, your feelings may be different.

 

[Byrd]

That’s a good way to put it LaPorta - keep the spinning rust drives for nostalgia, but they’re much less reliable than retrofitted SSDs. The amount of times I’ve come across a crashed SCSI HD, even in the 90’s was very common.

 

[0xABE]

Thanks for everyone‘s input. I agree that a good backup plan is needed no matter what.

All things considered I will go with the SCSI2SD and plan on keeping backups. Does anyone have experience with SCSI2SD-v5.5? https://store.inertialcomputing.com/product-p/scsi2sd-v5.5.htm

I’m not crazy about the extra depth it will add in the back, but having the SD card external to the computer would make it easier to access and I’ll be much more likely to follow through on making regular backups.

When I reassemble everything I’ll have to see if pin 25 on the DB25 has 5V. I suspect it will given that Inertial mentions the pizza box style case in the description.

 

[Trash80toHP_Mini]

I've got an adapter cable that plugs into Micro-SD and terminates in full size SD, IIRC. With an adapter in SCSI2SD you could probably run it to the security lock slot of just about any 68K Mac if you're willing to mod the inside of the case a bit. That's all in the ISTR category, haven't played with it seriously yet. Wouldn't need to worry about pulling the connection loose in a compact, pretty sure it was long enough for installation.

 

[LaPorta]

The only issue with the 5.5 version is speed: it runs at about 1 MB/sec, which is slower than the 2-3 MB/sec of the 5.1. On a Quadra 660 it shouldn't be too bad. You may have a good solution there, however, if you plan to back it up by taking the card out: over time, repeatedly lifting a 660's tabs may put a lot of stress on that plastic. On the flip side, V 51 has through-holes where you can solder a DB-25 port and connect it externally (it would still need USB power). Third, you could get the best of both worlds by getting some old SCSI HD external enclosure and modify it to easily access the SD card and USB port. It will have that old-school look and connect to your Quadra with a cable and ave space

 

[ArmorAlley]

However, I have read that flash memory degrades with every write and rewrite. So I am torn. I wonder about the effects of long-term usage on reliability with SCSI2SD.

Do also bear in mind that the 50-pin drives that you would be using are 20+ years' old and may have a lot of miles on them

Flash memory does degrade but it still has a life span of many, many years. I still have an IDE SSD from 2008 that's going strong. I have old 512MB SD cards from before then that still work.

To be sure, I have had SD cards fail on me, but then I've had hard-drives fail on me too (or, at least, require some psychiatric care).

For your 660av, I would consider the main benefits of SSDs: much, much less heat generated; much less power used (less of a strain on the PSU as well as costing less and writes & random reads are faster. Because it is much smaller, there is more space and better airflow.

The main disadvantages are the cost (they are quite pricey) and the setup.

 

[LaPorta]

To add to above, one of the best things is how easy it is to back up. Pull the SD, insert into new machine, make disk image, pull back out, good to go. If the SD fails, but new one for $7, copy backed up image to new card, and you are good to go.

 

[0xABE]

The only issue with the 5.5 version is speed: it runs at about 1 MB/sec, which is slower than the 2-3 MB/sec of the 5.1. On a Quadra 660 it shouldn't be too bad. You may have a good solution there, however, if you plan to back it up by taking the card out: over time, repeatedly lifting a 660's tabs may put a lot of stress on that plastic. On the flip side, V 51 has through-holes where you can solder a DB-25 port and connect it externally (it would still need USB power). Third, you could get the best of both worlds by getting some old SCSI HD external enclosure and modify it to easily access the SD card and USB port. It will have that old-school look and connect to your Quadra with a cable and ave space

I was under the impression that the v5.5 attached externally. Right, I was thinking I could avoid putting a lot of wear and tear on the tabs. I'll have to take another look, especially after you brought the speed specs to mind. I like your idea of modifying an external enclosure ... if I can find one at a reasonable price

 

[0xABE]

Do also bear in mind that the 50-pin drives that you would be using are 20+ years' old and may have a lot of miles on them

Flash memory does degrade but it still has a life span of many, many years. I still have an IDE SSD from 2008 that's going strong. I have old 512MB SD cards from before then that still work.

To be sure, I have had SD cards fail on me, but then I've had hard-drives fail on me too (or, at least, require some psychiatric care).

For your 660av, I would consider the main benefits of SSDs: much, much less heat generated; much less power used (less of a strain on the PSU as well as costing less and writes & random reads are faster. Because it is much smaller, there is more space and better airflow.

The main disadvantages are the cost (they are quite pricey) and the setup.

I'm disappointed to learn I can't install a more modern SSD like I run in my modern PC. The Q660 has a SCSI interface. The HD that came with it is original and still works. Very surprising! (and I really like the sounds it makes). I'll have to record the sounds for posterity

 

[ArmorAlley]

I'm disappointed to learn I can't install a more modern SSD like I run in my modern PC. The Q660 has a SCSI interface. The HD that came with it is original and still works. Very surprising! (and I really like the sounds it makes). I'll have to record the sounds for posterity

Actually, you can (at least, I fairly sure it would work) but the adapters are expensive and the improvement isn't great. The limiting factor is the 5MB/s SCSI bus.

A company by the name of Acard makes an IDE to 68-pin SCSI adapter. If you can find one, it will set you back a couple of hundred dollars. Added to that you need an IDE to SATA adapter (although an IDE to mSATA might be better). As well as that, you'll need a SCSI 68-pin to 50-pin adapter. These can be gotten from China for $10. This should work but since I've never tried it, I can't vouch for it.

However, since you can get 2 or 3 SCSI2SDs for the same price, I recommend the SCSI2SDs. Fewer cables. More space for cooling to circulate inside your Mac.

Another idea for speed, although it is hassle is to get a 64MB SIMM and set up a RAM-drive. Boot first from an external HD (or floppy), copy the system folder across to the RAM disk, reboot from the RAMdisk with the external HD turned off. It is as fast as SCSI2SD (well, it is on my Performa 475). It helps if you have a network handy to copy/save files. The machine is quiet and responsive, but still requires two boots whenever you want to use it. You also have less RAM at your disposal but you don't really more than 16MB anyway.

 

[Cory5412]

However, I have read that flash memory degrades with every write and rewrite.

This was only ever true for writes, and even then mostly stopped being true for mainstream computer SSDs a decade ago. For the type of work a Quadra 660 is capable of, a good high end SD card, which is recommended, will last for Quite A While.

The other aspect of this is that with sufficient memory, even with virtual memory turned on, Classic Mac OS does almost no random disk writes for no good reason, the way modern computers do. (For example, most modern web browsers, near constantly write data to your hard disk, which is what allows quick crash/tab recovery, and continuous updating text editors like Atom and VS Code do something similar.)

More importantly, there's a dwindling supply of working mechanical SCSI HDDs that are suitable for these machines.

The 660 with 7.6.1 or 8.1 will happily run very very large disks, so if you found the right chain of adapters and a 300 gig server disk, for example, it would work, but as has been mentioned, cooling will be an issue, especially if your 660 has a CD drive and any cards installed.

If your 660 has a working disk now, it's not a bad idea to get a SCSI2SD to use as a backup, or back up important data on it to a server (whether that's an a2server or something off-site such as vtools) and make sure you have bootable media to recover/reinstall from.

A future project I'd like to do, unless someone else wants to do it sooner, is to build, say, 7.1 Pro, 7.5.5, and 7.6.1 media that has the necessary upgrades pre-integrated on the CD. (Ideally: it's just a pre-patched installation distribution, but in reality it'll most likely be a set of SimpleText documents showing what to install, along with some other common getting started items, such as Stuffit and Disk Utility and an FTP client or web browser.)

If you were feeling really extravegant or you had several old Macs you wanted to reinstall often, a SCSI2SD v5.5 with one or more SD card set up to do installs on a few different types of Macs would be a neat addition to a toolkit, and would ease the pain of having dying/dead CD or floppy drives.