Kernel Compilation for Dual Xeon system
I am about to compile an optimized Kernel for my new servers. I'm used to compiling kernels but not for this specification of machine - these servers are all Dual P4-Xeon 2.2GHz (512Kb cache) using Intel E7500 (Plumas) chipsets, ECC DDR RAM.. - which processor type to select - I assume Pentium-4 since no Xeon option. - how much High Memory Support - some of these servers have 2GB, some 1GB RAM. I don't foresee expanding the RAM beyond 4GB in the future. - what to set for User address space size - why? Finally. Some of these servers will be high-throughput number crunchers and I have been advised by the software vendor to switch off hyper-threading in the BIOS (which I have done) as their tests indicate it degrades compute intensive tasks. But one server will be a general purpose machine and from Intel's pages it sounds like hyper-threading would be good for this. Anyone have experience with this? Are there any Linux specific optimizations? TIA -- Simon Oliver
I am about to compile an optimized Kernel for my new servers. I'm used to compiling kernels but not for this specification of machine - these servers are all Dual P4-Xeon 2.2GHz (512Kb cache) using Intel E7500 (Plumas) chipsets, ECC DDR RAM..
- which processor type to select - I assume Pentium-4 since no Xeon option.
- how much High Memory Support - some of these servers have 2GB, some 1GB RAM. I don't foresee expanding the RAM beyond 4GB in the future.
- what to set for User address space size - why?
Finally. Some of these servers will be high-throughput number crunchers and I have been advised by the software vendor to switch off hyper-threading in the BIOS (which I have done) as their tests indicate it degrades compute intensive tasks. But one server will be a general purpose machine and from Intel's pages it sounds like hyper-threading would be good for this. Anyone have experience with this? Are there any Linux specific optimizations?
TIA Hyper-Threading will not give satisfactory performance except with HT support enabled in the kernel. I believe this is the default in SuSE 8.0, but not with earlier kernels. If your kernel has HT enabled and the correct boot
On Monday 01 July 2002 04:47, Simon Oliver wrote: parameters specified, it will "Do The Right Thing" when booting, either with HT on or off. If your application is multi-threaded and employs the cache and write-combining buffers fully when only 2 threads are active, your vendor's recommendation is likely to be correct for this model. "General Purpose" might mean many things. HT usually gives 10% to 20% improvement in performance of parallel make, or a significant reduction in error rate with voice recognition applications. Maybe an increase in the number of clients supported by a web server, but I'd stay away from combining that with "general purpose." The performance advantage of HT could be capped by limited RAM or the lower performance of the DDR (if it is only the 100 Mhz variety), in comparison with similar models which use RDRAM. I don't speak for my employer, nor do I have experience specifically with SuSE on these machines. -- Tim Prince
participants (2)
-
Simon Oliver -
Tim Prince