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By | Timothy Prickett Morgan 13th April 2010 16:27

IBM sharpens Power7 blades

Twice the oomph. For less

IBM seems to finally be getting serious about Power-based blade servers. Today's launch of the Power Systems 701 and 702 blades, which use the new eight-core Power7 chips, offer about twice the performance of their predecessors, the JS23 and JS43 machines that were delivered using dual-core Power6+ chips last April. The use the same snap-together design of the JS23 and JS43 machines, but have half the processor sockets and lower prices too.

The relatively low prices for the PS701 and PS702 blades are intended to push back against the impressive bang for the buck that the just-announced Xeon 5600 and 7500 processors from Intel and the Opteron 6100s from Advanced Micro Devices are offering in entry rack and blade servers. The price/performance of the PS701 and PS702 blades also presages the forthcoming Power 720 announcement, very likely to be a two-socket server using Power7 chips coming from IBM later this year.

And IBM could also put out a very aggressively priced single-socket entry box aimed at small and medium businesses with fairly fixed and modest workloads, akin to the Smart Cube appliances that IBM has been selling as a kind of modern-day AS/400 in India and then the United States. (Yes, the Smart Cubes were introduced to those two geographies in that order, and they are not available elsewhere yet). With half-dud Power7 chips being a dime a dozen, IBM will try to remove as many from the scrap heap as possible and put them to good use.

The PS701 blade is a single-socket blade server, unlike the two-socket JS23 blade server it replaces in the Power Systems lineup and more like the JS12 blade that IBM introduced in April 2008 with a dual-core Power6 chip. Back then, IBM had a two-socket blade, the JS22, and that was it in terms of scalability. But in April 2009, IBM took a page out of its Opteron server playbook and created a two-socket blade server that had built-in SMP ports across the HyperTransport bus, so two two-socket blades could be snapped together to create a double-wide blade with twice the sockets (and cores) and twice the main memory.

Such a double-wide blade was called the JS43 with the Power6+ lineup, and with the Power7 machines, the double-wide is called the PS702. IBM's new HX5 blades, based on Intel's "Nehalem-EX" Xeon 7500s, also have this double-wide architecture for SMP expansion, but it is obviously based on a different chipset than the one used in the Power Systems machines.

With the PS701 blade, IBM is keeping it simple. There is one processor SKU at this time: an eight-core Power7 running at 3 GHz. That's it. The blade has sixteen DDR3 memory slots, topping out at 128 GB using 8 GB memory sticks (the fattest ones that Big Blue supports at the moment on Power7 iron). The PS701 blade has a slot for a single 2.5-inch disk drive, which is a SAS unit with either 300 GB or 600 GB capacity. The PS701 blade has a dual-port Gigabit Ethernet controller, a SAS disk controller, a service processor, two USB ports and two PCI-Express mezzanine cards for connection to external storage or networks.

Mommy blade meets daddy blade

The PS701 can be plugged into IBM's existing 9U BladeCenter H chassis (which as room for fourteen blades), the 7U BladeCenter S chassis (aimed at office environments and having room for six blade and two storage modules with a total of a dozen disk drives), and the ruggedized 8U BladeCenter T chassis (with DC power and other features telcos and service providers need).

IBM Power 701 and 702 Blade Servers

When a mommy PS701 blade and a daddy feature 8358 SMP expansion blade love each other very much . . . .

A variant of the PS701 blade called feature 8358 has the SMP expansion feature added and the service processor removed, and it is this that snaps onto the PS701 to turn it into a two-socket PS702 blade with 16 cores, 32 memory slots, and two disk bays.

A base PS701 comes with 16 GB of memory (four 4 GB sticks or two 8 GB sticks, you choose and you should choose the latter), and no disk. It costs $5,503. If you don't buy preconfigured BladeCenter PS701 or 702 Express setups, you have to activate all of the cores on the blades, which cost $100 per core to activate. It costs $799 to add two 4 GB memory sticks and $1,899 to add two 8 GB sticks.

The 300 GB 10K RPM SAS disk costs $689, while the 600 GB unit costs $899. (It is a bit mysterious why IBM doesn't offer a solid state disk on this blade, but that far, it does not). So a properly configured PS701 blade with all of its cores activated, 64 GB of memory, and a 300 GB disk for local storage, and a 3 Gb/sec SAS pass-through module to SAS disk modules in the chassis (assuming you want local disk) has a list price of $12,939.

A PS701 blade so loaded has a performance rating of 81.24 on IBM's rPerf (relative performance) online transaction processing benchmark test and compared quite favorably to a loaded JS23 Power6+ blade from last year, which topped out at 64 GB of main memory and an rPerf rating of 36.28 using four 4.2 GHz cores. IBM has radically dropped the clock speed, but faster DDR3 main memory and that huge 32 MB eDRAM L3 cache on chip (compared to the off-chip L3 cache on the Power6 and Power6+ designs) makes a big difference in performance. A base JS23 blade with all four cores activated, 4 GB of memory, and a 73.4 GB SAS disk cost $8,910; adding another 28 GB of memory to reach 32 GB total and the pass-through module to make a fair comparison would raise the price to $15,011.

IBM BladeCenter With Power7 Servers

. . . you get one big happy BladeCenter Power Systems family.

When you do the math, the PS701 costs $159 per rPerf unit of performance for the hardware, while the JS23 costs $414 per rPerf. This is a big change in bang for the buck for IBM's Power blade hardware - like a factor of 2.6 better.

The math on the PS702 is just as dramatic in terms of the bare iron price/performance. A JS43 with eight 4.2 GHz cores, 8 GB of memory, and a single disk ran to $17,510 a year ago (and still does today, if you want to buy one). Beefing that puppy up to 64 GB of memory and adding the SAS pass-through module pushed the price of the JS43 up to $29,463, or $432 per rPerf unit of performance.

Making a PS702 blade with sixteen cores, 128 GB of memory, and one disk means shelling out $5,504 for the feature 8358 SMP expansion card (why it costs an extra dollar more than a base PS701 blade, I dunno), plus $800 for Power core activations, and $7,596 for another 64 GB of memory. That's a total of $26,839. The PS702 blade with all sixteen cores turned on is rated at 154.36 on the rPerf test, so that works out to $174 per rPerf unit of performance, or a factor of 2.5 improvement.

This is not the typical, conservative price/performance gain you see out of Big Blue.

The PS701 and PS702 blade servers support IBM's AIX 5.3 and 6.1 Unix variants provided they have the right patches, as well as its own i 6.1.1 or i 7.1 proprietary operating system - the latter of which was also announced today. The Power7-based blade servers can also run Red Hat Enterprise Linux 5.5, which was just tweaked two weeks ago to support the Power7 chips as well as all the new x64 processors from Intel and AMD. Novell's SUSE Linux Enterprise Server 10 SP3 will support the new Power7 blades, but you're going to have to wait until SP1 to get SLES 11 for these machines.

The PS701 and PS702 blades will ship on June 4. ®

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