Supermicro SC846 Model Confusion

[BecauseScience]

I need some help so I don't buy the wrong SC846 chassis.

I'm going to list the various SC846 variants and what I think the features / differences are. Please correct me if I'm wrong about something and fill me in if I've missed a feature / difference. I'm limiting it to models with platinum psu's because that's what I want.

Things that appear to differ between models:

• number of expansion slots
• number of rear 80mm fans
• multipath SAS or not
• SAS expander or not
• psu wattage
• location of psu's (under the motherboard or on the back left side)
• location of 2.5" hotswaps (under the motherboard or on the back left side)

These first three models look identical. How do they differ?
(Note: Post edited to move this question to the top. For some reason I originally wrote it *after* the three chassis. Duh.)

846XA-R1K28B

• 13 slots
• 1 rear fan
• expander - YES
• multipath SAS - YES
• two optional 2.5" hotswap bays (rear under motherbroard)
• redundant 1280w platinum psu's (under motherboard)

Is that room for two additional psu's between the existing psu's and the 2.5" hotswaps?

846XE26-R1K28B

• 13 slots
• 1 rear fan
• expander - YES
• multipath SAS - YES
• two 2.5" hotswap bays (rear under motherbroard)
• redundant 1280w platinum psu's (under motherboard)

846XE16-R1K28B

• 13 slots
• one rear fan
• expander - YES
• multipath SAS - YES
• two optional 2.5" hotswap bays (rear under motherbroard)
• redundant 1280w platinum psu's (under motherboard)

846BE16-R1K28B

• 7 slots
• two rear fans
• expander - YES
• multipath SAS - NO
• two optional 2.5" hotswap bays (rear left side)
• redundant 1280w platinum psu's (rear left side)

846BE16-R920B

• 7 slots
• two rear fans
• expander - YES
• multipath SAS - NO
• two optional 2.5" hotswap bays (rear left side)
• redundant 920w platinum psu's (rear left side)

Difference between this and 846BE16-R1K28B psu wattage.

846BE26-R1K28B

• 7 slots
• two rear fans
• expander - YES
• multipath SAS - YES
• two optional 2.5" hotswap bays (rear left side)
• redundant 1280w platinum psu's (rear left side)

846BE26-R920B

• 7 slots
• two rear fans
• expander - YES
• multipath SAS - YES
• two optional 2.5" hotswap bays (rear left side)
• redundant 920w platinum psu's (rear left side)

Difference between this and 846BE26-R1K28B is psu wattage.

846BA-R1K28B

• 7 slots
• two rear fans
• expander - NO
• multipath SAS - NO
• two optional 2.5" hotswap bays (rear left side)
• redundant 1280w platinum psu's (rear left side)

846BA-R920B

• 7 slots
• two rear fans
• expander - NO
• multipath SAS - NO
• two optional 2.5" hotswap bays (rear left side)
• redundant 920w platinum psu's (rear left side)

Difference between this and 846BA-R1K28B is psu wattage.

846A-R900B

• 7 slots
• two rear fans
• expander - NO
• multipath SAS - NO
• two optional 2.5" hotswap bays (rear left side)
• redundant 900w platinum psu's (rear left side)

Difference between this and 846BA-R920B is psu wattage.

I want a chassis with 1280w psu's and expander but without multipath. It looks like 846BE16-R1K28B is the one I should get. Am I right?

 

[unhappy_mage]

url="http://www.supermicro.com/products/chassis/4U/846/SC846XA-R1K28.cfm"]846XA-R1K28B[/url]
Is that room for two additional psu's between the existing psu's and the 2.5" hotswaps?

Not sure, actually.

846XE26-R1K28B
846XE16-R1K28B
These first three models look identical. How do they differ?

846A = 6 SAS wide ports, SFF-8087, one path to each drive
846E16 = Single SAS expander chip, one SFF-8087 exposed to connect to HBA and two to daisy-chain to other enclosures. One path to each disk; sufficient for sata disks and single-port SAS drives.
846E26 = Two SAS expanders, each connected to all the drives in the same way as the E16 model. This is useful for dual-ported SAS drives or other drives with interposers only.

Page D-11 in the SC846 manual explains some of this.

I want a chassis with 1280w psu's and expander but without multipath. It looks like 846BE16-R1K28B is the one I should get. Am I right?

Yes, that looks right. The "B" in 846BE16 means they have the 2.5" hotswap drives on the rear, "E16" means one 6gbps-capable expander, R for rackmount (duh), "1k28" for 1280W PSU, and B for black colored faceplate.

 

[BecauseScience]

846A = 6 SAS wide ports, SFF-8087, one path to each drive
846E16 = Single SAS expander chip, one SFF-8087 exposed to connect to HBA and two to daisy-chain to other enclosures. One path to each disk; sufficient for sata disks and single-port SAS drives.
846E26 = Two SAS expanders, each connected to all the drives in the same way as the E16 model. This is useful for dual-ported SAS drives or other drives with interposers only.

Page D-11 in the SC846 manual explains some of this.

Thanks for the manual pointer. I'll check it out.

I caught onto the A, E16, E26 pattern being no expander, expander, and multipath. However, I was confused by the 846XA-R1K28B, 846XE16-R1K28B, and 846XE26-R1K28B because the Supermicro pages for all three say "Dual Expander." It seems like a serious error to make on a specs page.

So if the 846XE16-R1K28B does have a single expander (no multipath) then it should also fit my buying criteria. I guess it comes down to 13 slots vs 7 slots and the alternate psu & 2.5" hotswap positioning.

Actually, it looks like there is more headroom for a cpu cooler on the 7 slot models than the 13 slot models. I can't foresee ever using 13 slots so I'll take the additional cooler room.

The "B" in 846BE16 means they have the 2.5" hotswap drives on the rear, "E16" means one 6gbps-capable expander, R for rackmount (duh), "1k28" for 1280W PSU, and B for black colored faceplate.

Awesome! I was wondering what the "code" was for the different parts of model number.

I have a few questions about what I need to order in the way of cables and whatnot but I think that's best done in a build thread.

 

[mini-me01]

You are also likely to find a better price on the 7 slot models and the 13 slot models were just released. Functionally the two versions appear identical, it all comes down to whether you require the two 2.5 hotswap drives on the outside.

Most of the systems on eBay seem to be the "TA" version with 24 individual SAS/SATA cables feeding the backplane. If you are looking for the expander version you should also consider adding the sc847 to your search which always has an expander "E16" or "E26" backplane and 36+ drives (front and back)

 

[BecauseScience]

Most of the systems on eBay seem to be the "TA" version with 24 individual SAS/SATA cables feeding the backplane. If you are looking for the expander version you should also consider adding the sc847 to your search which always has an expander "E16" or "E26" backplane and 36+ drives (front and back)

I will definitely go for a model with built-in expander. I don't want to mess around with multiple HBA's or fitting a discrete expander.

I saw the 847 line. While it would be fun to say I had space for 36 drives, I don't see myself needing the space any time soon, especially with the larger capacity drives on the way.