Author Topic: SAS/SATA idea  (Read 1102 times)

Offline (S)ATAman

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SAS/SATA idea
« on: December 08, 2019, 03:08:04 PM »
I am curious, what people would think about something like this

https://www.ebay.com/itm/LSI-Logic-SAS3801X-PCI-X-External-SAS-HBA-3GB-S-Controller-Card-w-Low-Profile/232366162289

for their G4-s and G5-s?

The drivers (OF, MacOS 9, macOS-X) shouldn't be a problem. The supported OS should be 9.x (no 8, sorry) and 10.3.x +, maybe even 10.4.x+
I do not want to deal with anything earlier.

These LSI SAS cards start to appear in bigger numbers and prices can be very low. The architecture is quite well-documented, but firmware varies a lot. I have no experience with microcode-based RAID, so if the future would bring anything, it's just "IT" mode (in LSI lingo).

This would be something like a side-effect of very different thing, but please keep in mind: the drivers will be copy-protected and no cross-flashing!
It's SAS, so here things can be done a bit more efficiently than just to "tie" the driver to a certain kind of flash ROM.
Sorry about it...

But if there is a demand, I can dedicate some time (upon approval of the management, of course).

Offline (S)ATAman

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Re: SAS/SATA idea
« Reply #1 on: December 08, 2019, 03:31:06 PM »
Just got a "victim", with love from Russia, see the auction.

https://www.ebay.com/itm/LSI-SAS-Megarad-8204XLP-PCI-X-133/274039223289

It's a software RAID card, not hardware RAID, so should be perfect.

I just got MPT-2, MPT-2.5 drivers working on everything from Leopard to Catalina. And it's bootable, at least on the Cheese Grater.
Did not try on other Macs yet.

So let's see how the old MPT does fare, I think the card from Russia is less, than MPT-2 but I will see as soon as it arrives from Ekaterinburg.
To bad, MPT-2 and MPT-2.5 is all PCIe, but MPT could be PCI-X as well. These "MPT"-s are generations of LSI SAS.

The speed (only 3 Gbit) is a compromise, but on the other hand these cards can handle >2 TB drives.
And while most SATA drives are OK, I can't use AData DP910 SSD with MPT 2.5 (9300) card, I tried hard - does not work. Other SSD-s seem to be OK.

One more thing. It is extremely unlikely I would write an OF driver with > 2TB support, see my other posts.
But other than that, do not see, why not. Just be patient...
« Last Edit: December 08, 2019, 03:44:09 PM by (S)ATAman »

Offline IIO

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Re: SAS/SATA idea
« Reply #2 on: December 08, 2019, 05:37:55 PM »
The speed (only 3 Gbit) is a compromise, but on the other hand these cards can handle >2 TB drives.

both is not required for OS9. just saying.
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Offline (S)ATAman

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Re: SAS/SATA idea
« Reply #3 on: December 08, 2019, 11:25:03 PM »
The speed (only 3 Gbit) is a compromise, but on the other hand these cards can handle >2 TB drives.

both is not required for OS9. just saying.

Yes, but it is possible to get into a trouble. So special care has to be taken because realistically even hard-core users of MacOS 9 may want to boot into macOS-X. Which may reside in the same partition. On a disk which macOS-X does "see" as 3TB - but Open Firmware does see only the first 2 TB.

Here I am not 100% sure because the last time I touched Open Firmware was over 10 years ago - but as I remember, I always got 32-bit LBA addresses in the I/O requests. That means: the highest LBA address is 0xFFFFFFFF. And since OF would deal with 512-byte sectors, the limit is 512 * 0x100000000 bytes. That gives us precisely 2,199,023,255,552 bytes or 2TB.

Apple went around this problem by introducing within Open Firmware their own 48-bit calls inside of their own flavor of SATA (I am talking about MDD and Cheese Grater machines). For a third-party it is not safe to use them and these calls could vary from model to model. What remains for us is the generic drive package with as I recall max. 32-bit addresses.

Regarding the 3Gbit speed limit - that means you can't transfer over ca. 250 - 300 MB / Sec. The 64-bit 66MHZ PCI is capable of about double.
A single SSD means that you saturated the SAS phy of the controller without saturating the controller bandwidth.

So people would have to live with that. On the other hand the hardware itself becoming very cheap. The main business would be probably popularize that solution. I remember the time when a decent 4-channel 150 MByte/Sec SATA-I controller would cost close to $200. Today you can get a decent 12 Gbit (say, 1 Gigabyte / Sec) SAS controller for less than that. The same time a decent SATA-III controller is at least $50. Except that the SATA-III controller is only PCIe 2x and port multipliers are far more expensive than second-hand expanders.

I got recently a 16-port IBM expander card with fail-over for under $15. Try that with a port multiplier...

This one - works perfectly:

https://www.ebay.de/itm/IBM-46m0997-ServeRAID-Expansion-Adapter-16-port-SAS-Expander/192326557905

Don't be afraid of the PCIe-looking bus of the expander. It is just for the power. Right now I am using a very simple adapter to power it:

https://www.ebay.de/itm/USB3-0-Pcie-PCI-E-Express-1x-bis-16x-Extender-Riser-Kartenadapter-Netzkabel-60cm/132428653550

The SAS expander goes into 16x PCIe slot which is just hanging in the air. The power cable is attached to the motherboard-based power connector of 2009 Mac Pro where normally the high-end graphics is powered from, there are two of these even in G5.
The graphics card is the lowest of the low GT-120, in this project I don't care less about the graphics.

Some collection of SAS cards, the said IBM expander included on this picture. One extra with hopefully Open Firmware coming from a French seller, an other one with OF from Germany and one with PCI-X instead of PCIe coming from Russia. All slightly different flavors, it's all-you-can-eat SAS time for me.
« Last Edit: December 08, 2019, 11:57:01 PM by (S)ATAman »

Offline IIO

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Re: SAS/SATA idea
« Reply #4 on: December 09, 2019, 04:34:15 AM »
for the 64 bit slot in an MDD it might make sense. at least in an extreme testing scenario. :)
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Re: SAS/SATA idea
« Reply #5 on: January 10, 2020, 08:08:13 AM »
if you can make it work bootable then we are all cheering you on  8) ;D

Offline Melkhior

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Re: SAS/SATA idea
« Reply #6 on: July 16, 2020, 05:25:28 AM »
For the 1064/1068 (PCI-X) & 1068e (PCIe), first gen SAS (complete with a hardware bug limiting SATA to 2TB), a 'workable' (with a huge caveat!) solution: <http://www.sunhelp.org/pipermail/rescue/2020-July/142265.html> (and here for the procedure: <http://www.sunhelp.org/pipermail/rescue/2020-July/142244.html>).