1) I found more verbiage for the EJ0P.
2) What is the actual feature for the intergraded SAS controller, or doesn't it have one?
3) Would the integrated controller be very similar to EJ0J PCIe3 RAID SAS Adapter Quad-port 6Gb x8 or is this a different animal?
4) The DVD would be dedicated to this LPAR and capable of being DLPAR, correct?

When you choose the optional #EJ0P storage backplane, the controller is replaced by a pair
of High Performance RAID controllers with dual integrated SAS controllers with 1.8 GB of
physical write cache. High performance controllers run 18 SFF-3 SAS bays, 1.8-inch SSD
cage bays (only available on the Power S824), and a DVD bay in the system unit. Dual
controllers (also called dual I/O adapters or paired controllers) and their write cache are
placed in integrated slots and do not use PCIe slots. However, cache power protection
hardware covers one PCIe x8 slot (P1-C11). Patented active/active configurations with at
least two arrays are supported.
The write cache, which is responsible for increasing write performance by caching data
before it is written to the physical disks, can have its data compression capabilities activated,
providing up to 7.2 GB effective cache capacity. The write cache contents are protected
against power loss by flash memory and super capacitors, which removes the need for
battery maintenance.
The high performance SAS controllers provide RAID 0, RAID 5, RAID 6 and RAID 10
support, and its EasyTier variants (RAID 5T2, RAID 6T2, and RAID 10T2) if the server has
both HDDs and SSDs installed.

2.6.4 Media bays
Included in the EJ0N or EJ0P backplanes is a slimline media bay that can optionally house a
SATA DVD-RAM (#5771). Direct dock and hot-plug of the DVD media device is supported.
The DVD drive and media device do not have an independent SAS adapter and cannot be
assigned to an LPAR independently of the HDD/SSDs in the system.


-----Original Message-----
From: MIDRANGE-L [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Sue Baker
Sent: Tuesday, December 01, 2015 2:54 PM
To: midrange-l@xxxxxxxxxxxx
Subject: Re: Perf difference between EJ0L PCIe3 12GB Cache RAID SAS Adapter vs integrated EJ0J PCIe3 RAID SAS Adapter Quad-port 6Gb x8

"Steinmetz, Paul"
<PSteinmetz@xxxxxxxxxx> wrote on
Tue, 01 Dec 2015 17:43:35 GMT:

Because the P8 S824 CEC DASD must be controlled by the integrated EJ0J
PCIe3 RAID SAS Adapter Quad-port 6Gb x8, I would like to know how much
of a performance difference there would be seen between the EJ0L PCIe3
12GB Cache RAID SAS Adapter vs integrated EJ0J PCIe3 RAID SAS Adapter
Quad-port 6Gb x8?

This is not correct.

S824 has 3 options for its DASD backplane and one of these must be selected. Sales manual pages say

Choose storage backplane from:

- Twelve SFF-3 Bays/DVD Bay (#EJ0N).
- Eighteen SFF-3 Bays/ eight 1.8-inch SSD bays/DVD Bay/Dual
IOA with Write Cache (#EJ0P).
- Split feature EJ0N to 6+6 SFF-3 Bays: Add a second SAS
Controller (#EJ0S).

I guess you could consider the EJ0N and EJ0S as similar to the EJ0J since none of these features has write cache. The EJ0J only connects to ESP24S disk enclosures.

As to performance of EJ0P compared to EJ0L and/or 5913/ESA3 adapters. It falls precisely 1/2-way between the adapters.

This thread ...


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