POWER9 – Which is Better: Internal or External Storage?

Most IBM i customers have an ERP package on their IBM Power server that runs their business.  Typically, a small or mid-sized company can comfortably operate with one Power9 core activation, that provides a CPW of 13,125.  The IBM Power9 model S914 has two processor options, a 4-core, and a 6-core.  Which one do you get if you only need 1 core activation?  The 4-core server is physically the same as the 6-core server, except for the processor and the other differences shown in the table below.

Feature 4-core 6-core
Maximum Cores 4 6
Maximum Memory 64GB 1TB
Maximum Internal Disk Drives 10 (283GB HDD or 387GB SSD) 672, many HDD & SSD sizes
BUS Expansion None 1 drawer – 6 adapter slots
Software Tier Group P05 P10

Let’s discuss each of these differences in more detail:

Maximum Cores – 4 vs. 6 is not an issue.  Most customers only need 1 core and very, very few customers activate more than 4 cores.  Verdict:  Not an issue.

Maximum Memory – 64GB vs. 1TB is a big difference.  But, for a server using just a single core activation, 64GB is more than adequate.  64GB of memory should also be OK for 2 core activations.  Verdict:  Not an issue for a 1-core system.

BUS Expansion – the 4-core does not allow any BUS expansion, but so much is built into the S914 base system unit, very few servers need more than the 7 adapter slots in the system unit.  Verdict: Not an issue for most users.

Maximum Internal Disk Drives10 drives vs. 672 drives is a huge difference, but one that can be overcome using external storage.  Verdict:  the 6-core is better, but can be made not an issue by using external storage.

Software Tier Group – This is a big difference, the lower the tier group, the lower the cost of software licensing and maintenance.  P05 is going to be at least 50% less expensive in software licensing and ongoing software maintenance.   Verdict:  the 4-core (P05) is better.

IBM External Storage, called Storwize, was at first shunned by IBM i customers, but now is gaining traction because of:  new features, flexibility, cost and performance considerations.

The features include:

Cloud-enabled, deduplication, compression, flash copy, thin provisioning, encryption, clustering, Easy Tier, and remote mirroring.  External storage can be shared by multiple servers with different operating systems, like Windows and LINUX.

Even if you just need plain disk, without all the fancy extra features, check out the numbers for two similarly configured servers needing 7TB of SSD storage.  The 4-core server has no internal disk, but uses a Storwize 5010e. The 6-core server has 18 x 387GB SSD’s in the system unit.  Both configurations include 1 processor core license, unlimited users and 3 years 24×7 warranty coverage.  IBM list prices are shown.

Component 4-core 6-core
IBM Power9 S914 Server $19,796 $65,227
IBM Storwize 5010e $19,857
Software – OS 1 core license $2,245 $14,995
Software – OS Unlimited Users $20,000 $50,000
HW Warranty to 3 years 24×7 $2,325 $1,250
SW Warranty to 3 years 24×7 $3,595 $9,760
Total $67,818 $141,232

Both the 4-core and the 6-core provide the same capacity and performance, but look at the difference in price, the 4-core is less than half the cost of the 6-core!  You may object, however, because you are not familiar with external storage.  External storage is the standard for most hardware platforms today.  They are easy to install and operate.  iTech Solutions has IBM Storage certified engineers and sales reps and iTech Solutions uses external storage for its cloud hosting business, iInTheCloud. 

For a server with 1 core activation and the need for more than 4TB of disk, a 4-core server with external storage is clearly the better deal.  But what if you need a larger server, one with more than 64GB of memory, is external storage still a good deal?  It depends.  Pricing on external disk could be better than internal disk.  And if you need some of the external disk features that are not available with internal disk, external disk is the better choice.

iTech Solutions can show you server solutions using both internal and external disk, point out the differences, and help you to make a decision that best works for you.  Why not give us a call?

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