icebrian :
Hello everyone,
I revert to these forums as I am unable to find any specific information.
Currently I have a HP RX7640 (http://h18000.www1.hp.com/products/quickspecs/12470_div/12470_div.PDF) with 6 Dual-core Itanium chips.
I am considering moving over to X86 and am trying to understand what Xeon chips would be the equivalent or better than the Itanium.
On the RX7640 I have 4 Vpar's. All are running various instances of Oracle BD's both EE and SE. I am only running BDs.
Not sure if this amount of information is enough but am hoping it is.
What would like to get is someone that could confirm the starting from a certain Xeon chip processing power will be equl to or better than 1 Itanium chip.
Thanks in advance,
Regards
This is very tricky to answer in real life. Most current x86_64 CPUs including the current Xeons are fairly narrow (3 or 4-issue) units with few registers (16) and large amounts of power and effort dedicated to out of order execution engines. Itanium is an extremely wide (11 issue)
in-order chip with a massive 128 registers that depends very heavily on the compiler to keep itself occupied. The Itanium also has a potential very powerful FMAC FPU that Intel has yet to replicate on any Xeon. AMD only recently put an FMAC FPU on an x86_64 CPU in 2011 with the "Bulldozer" AMD FX series and 3200/4200/6200 series Opterons. Itanium performance as a result is VERY sensitive to the particular code it is running and the compiler it is compiled with. You can have a MASSIVE difference in performance if you have branchy low-IPC code compiled with a poor compiler or poor options vs. hand-tuned, high-IPC code compiled with a compiler with the right magic juju to keep all 11 pipelines as full as possible. I have worked somewhat briefly with Itaniums for HPC and they can be very powerful or downright suck. Also, there is no direct apples-to-apples performance comparison using identical OSes and program binaries between the x86_64 Xeons and ia64 Itaniums because they have different ISAs and require different binaries.
My best guess is that your six-CPU Itanium system is probably on a good day about as fast as a modern six-core Xeon like an E5650 or E5-2620. The current Xeons are clocked much higher, have bunches of bandwidth due to their integrated memory controllers/point-to-point buses and have excellent SIMD capabilities and a bunch of cores. Your Itaniums are five years old, low-clocked, likely underutilized by less than perfect binaries, and bus-choked by their old FSB architecture. If you really want to guarantee that you end up with a faster system buy yourself a dual 8-core Xeon E5-26xx system or a dual 16-core AMD Opteron system.
icebrian :
Thanks Jay. I had actually already found these links. What I can see is that Intel sells the E7 as an equivalente it doesn't however include allot of information on why. Also I I still am in doubt if the there might be inferior Intel X86 processors to the E7 that could acomplish the same as the Itanium.
The E7 is an equivalent to the Itaniums because the E7s and the Itaniums are both very expensive, have the ability to be made into 4-CPU and greater systems, and have roughly similar RAS (reliability, availability, and serviceability) capabilities. E7s are very, very expensive because of their 4-CPU+ capabilities and you will do better with the two-CPU-only E5 series from a cost and performance standpoint.
In short, I recommend that you get yourself an inexpensive but decent desktop system such as an i5-3550K or AMD FX-8150 and run Linux on it, and see how it stacks up to the Itaniums running Linux. Base your server purchase accordingly based on the number of CPUs and clock speed you feel you need to get the performance you need.
Facebook
Twitter
Instagram