Difference between HP Integrity and HP Blade servers.

[NarendraUttekar]

Hi,

We are planning to purchase new HP servers. I want to know which will be the best server i.e Integrity or Blade servers in terms of performance.

Please can you let me know the important difference between HP Integrity (HP Integrity rx7640 Server – 8 CPU and 32GB RAM) and HP Blade (HP Blade BL870c i2 Server - 8 CPU and 32GB RAM) servers.

We will be running SAP ECC6.0 Application and database as MaxDB 7.7 with 300 con-current users.

Thanks,

Narendra

[Matti_Kurkela]

Integrity and Blade are not mutually exclusive: in fact, BL870c i2 is an Integrity Blade server.

"Integrity" means the server uses Itanium CPUs (so it can run HP-UX).

"Blade" refers to the physical form of the server: blade servers are designed to allow you to place a maximum number of servers in a minimum of space, but you need a special "chassis" to place the blade servers into. The blade chassis contains all the fans, power supplies and external I/O connections for the blades in it. You cannot run a single blade without placing it into a chassis.

The blade format can be useful if you want many servers with very similar I/O configurations, but if you need only one server and don't already have a blade chassis available, a non-blade ("stand-alone") server will be a better choice. With blades, the chassis I/O module configuration will restrict your configuration choices: even if you already have a blade chassis available, a stand-alone server might be a good choice if you need just one server with a very different I/O configuration.

Buying an entire blade chassis for just one or two blades would not be a good idea: the smaller c3000 blade chassis can take 4 full-height blades (or 8 half-height blades), and the more common c7000 chassis can take 8 full-height blades.

[NarendraUttekar]

Hi Matti,

Thanks for the reply…But I want to know whether there will be any performance difference between integrity and blade in terms of CPU and memory. And also we will connect i.e. Blade or Integrity servers to external storage i.e. SAN – EMC Clariion CX4-240 will that will have some performance problem with Blade servers?

Thanks,

Narendra

[Matti_Kurkela]

Here are the QuickSpecs documents for both servers.

HP Integrity BL870c i2 Server Blade:

http://h18006.www1.hp.com/products/quickspecs/13620_div/13620_div.HTML

HP Integrity rx7640 Server:

http://h18006.www1.hp.com/products/quickspecs/12470_div/12470_div.HTML

(Note: both of them are Integrity, but only one of them is a Blade.)

I would look at memory bus bandwidths to find any performance differences:

BL870c i2: "Memory Bus Bandwidth:4.8GT/s"

(This needs to be multiplied with the size of each transfer to know total bandwidth. We know the newest-generation Itanium CPUs use QPI technology, and each QPI transfer moves 64 bits = 8 bytes of data, so 4.8 GT/s = 38.4 GB/s.)

rx7640: "Each HP Integrity rx7640 Server cell board supports up to 16 DIMM slots and 16 GB/s of peak memory bandwidth." (You could get 8 CPU cores = 4 dual-core CPUs with just one cell board, but you might want to install both cell boards anyway to maximize memory bandwidth. 2 cell boards * 16 GB/s = 32 GB/s.)

Looks like the BL870c i2 is actually a bit faster than the rx7640! That makes sense, because the rx7640 is at least two years old model, and the blade is very new.

With the blade, the performance of the external storage connections may depend on the choice of I/O modules in the blade chassis: if you use a FC switch or a VirtualConnect module, the entire blade chassis will have just a few FibreChannel connections, which will be shared between all the blades in the chassis. But if you use FC Pass-Through modules, each blade will have completely independent FibreChannel connections, allowing full bandwidth to each HBA simultaneously. On the other hand, a Pass-Through module means you must run a lot more fiber cables to the blade chassis.

So the blade itself looks like a powerful beast, but you might want to pay careful attention to the I/O configuration and the choice of I/O modules in the blade chassis. It's certainly possible to get good storage I/O performance, if the chassis configuration is designed to support that.

[NarendraUttekar]

Hi Matti,

Once again thanks for the valuable suggestion. Looking at your review on both Rack and Blade…Blade looks like a good option in terms of performance and cost.  I have some few more questions as we are planning to use HP Integrity BL870c i2 Server as a Database and SAP central instance and HP Integrity BL860c i2 Server as an additonal SAP application server. The server BL870c i2 will have only external storage connection through optional (HP BLC EMULEX LPE1205 8GB FC HBA OPT). Then we will not require HP BLC VC FLEX-10 ENET MODULE OPT and HP BLC VC 8GB FC 20-PORT OPT KIT and HP BLC VC 1GB RJ-45 SFP OPT KIT correct? If we will require then please can you explain why those OPT KIT? We are already having the SAN switch that can we directly connect to the Blade Server HBA is that correct?

And also can we club 2 blade as a single physical server i.e. combining 2 blade servers Physical RAM and CPU?

I didn’t get you pay careful attention to the I/O configuration and the choice of I/O modules in the blade chassis. As we are going to connect blade server through optional (HP BLC EMULEX LPE1205 8GB FC HBA OPT) in that the I/O connection will be independent fiber channel connection to each blade server as it will directly connect through the SAN switch…

Thanks,

Narendra

[Matti_Kurkela]

A blade server by itself does not work: it needs to be plugged into a blade chassis, which can contain many blades.

The most common chassis for c-class blades is the c7000, which has 16 slots: a half-height blade takes one slot, a full-height blade like BL860c i2 takes two slots, and a double-wide blade like BL870c i2 takes four slots.

The chassis contains cooling fans, power supplies and I/O modules: these will be used by all the blades in the chassis. When you need many identical servers, blades are a very economical solution; but if you need just one or two servers, not so good.

If the SAP servers you mentioned will be your only blade servers, a c7000 would be overkill for you: more than half of its capacity would be unused. The smaller c3000 chassis might be a good choice.

On a stand-alone server like rx7640, a HBA is a just a PCI-X or a PCIe card. On a blade server, the functions of a HBA are split into two parts: 1.) the mezzanine card in the blade, and 2.) the I/O module in the chassis I/O slot.Without an appropriate FC I/O module, the OS of the blade will detect that a HBA exists, but there will be no physical connector for the fiber!

There is a limited number of I/O module slots, and each I/O module will be connected to every blade in the chassis, so your configuration is restricted: all the blades in one chassis must have similar I/O configurations. The first I/O module slot on a c3000 and the slots 1 and 2 on a c7000 are dedicated to integrated networking: to use the blades' internal NICs, you must always place at least one Ethernet I/O module to these slots.

And no, at this time you cannot combine 2 blades into a single server with regular blades. (Although there are ways to combine multiple blades into a single processing cluster, it is not quite the same thing as a single server. Such processing clusters usually require specialized software to use them effectively.)

If you are not familiar with blades, you should ask the HP sales agent to verify that your first blade hardware order will be a sensible, complete package.

It is easy to make silly mistakes if you're unfamiliar with blades: at our site, someone required a single Integrity server as a backup media server. He did not understand the properties of the blades, and chose a BL860 Integrity Blade server because it was cheaper than a traditional standalone server, and he knew that we already had deployed other blade servers successfully. But after the hardware was delivered, it was realized that none of our existing blade chassises were in the same datacenter as the big tape library... and there was no point installing an entire new chassis for just one blade.

So that was an expensive learning experience, but fortunately we could repurpose the blade to another project.