PC GAMESS/Firefly-related discussion club

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Denis Zavelev
denis.zavelev@gmail.com

>>Does your system work OK in case of heavy tasks that last e.g. several days?
>It has been stable for several days even when running with np=8 with htt. There were some issues with installation of the latest drivers for the Marvel ports (eSATA and IDE). An uninstall and reinstall fixes the problem.
Good!


>>What means "better"? Faster, more reliable?
>Both. This is a quality memory that the manufacturer advertises as designed for overclocking. It is not the cheapest on the market, but I thought it was worth the expense. I found some good reviews of it as well.
Thanks. I'm taking this into account.


>>Are you sure that 700W is enough for all those HDDs and coolers?

>I haven't had an issue with the PS. My graphics card is not very demanding, so maybe this is why. The Seagate drives draw max 9.4 W each, so even with heavy use the draw is not that high. The eSATA HD has its own PS.

No more questions concerning power...


>>>I looked at 10,000 rpm Western Digital drives, but they have a high failure rate and are very noisy.
>>Noise is not real problem, I suppose. Seagate HDDs are also not silent.
>I came across some significant complaints about those drives. Also, the bit density on the platters is much higher for the Barracuda 12 drives, so the advantage of the 10k rpm is diluted. Now, the 15k rpm Savvio is a different story... yes, it is a SAS 2.0 (6GB/s).
>The new Western Digital RE4 (2TB) is supposed to be faster in sustained transfer than the Barracuda 12 thanks to higher density (500GB per platter. It is slower in random access (14 ms vs. 4.17 ms for Barracuda), which is compensated to some extent by 64 MB cache. At 5400 rpm it is supposed to be very reliable with >1,200,000 h MTBF.


SAS is very expensive, so I'll probably choose either Barracuda 12 or WD RE4.


>>First of all, they are really expensive (even in comparison with SAS). Then I haven't seen SDDs bigger than 128Gb. Usually each cache is not much than 10Gb, but I heard that sometimes one of caches can be 200Gb or even bigger. And afaik SDDs can be incomparably less reliable than usual HDDs on such heavy duties.
>OCZ makes a 1TB SSD, it can do 878 MB/sec read and 781 MB/sec write sustained, which is about 8x faster than the 1TB Barracuda. It does cost a lot more than 8x Barracuda.
Yes, but we'll hardly buy 2x such SDDs. Having only one SDD (with 4 scratches on it) will hardly give better performance that 4 independent SATA II drives.


>I don't know about the reliability side. http://www.tomshardware.com/news/ocz-z-drive-ssd-pci-express-pcie,8589.htmlhttp://www.tomshardware.com/news/ocz-z-drive-ssd-pci-express-pcie,8589.html

SDDs are used in some netbooks (like famous Asus eeePC) and usually they die after 1.5-2 years of work. I suppose that Gamess scratches more intensively than WinXP home...


>>Damn, it's sad but it seems that I'll also have to use Vista64. :(
>>It's no problem to use some 64bit linux distribution (currently I prefer Ubuntu though AltLinux is also pretty except the stupid installer), but it doesn't work with any 64-bit MPI implementation, so we have to use only ~3.3Gb of memory.
>The Intel MPI works under Fedora 10 64-bit. For home use I got a free non-commercial license, together with their compiler suite. BTW, US-GAMESS is about 30% faster when compiled with Intel Fortran than with gfortran.

It's not a problem to find working 64-bit MPI. In Ubuntu repositories there are MPICH, LAM, OpenMPI.


>Windows Sever 2008 64-bit is probably a better solution than Vista. You can use it with Deino MPI (or Intel).

I dislike Windows... After many years of using Windows 2000 I went to Linux. At least it's more stable if tuned good.


>>Maybe it's just a question of "religion". For usual cheap desktops I prefer to use AMD, but if it concerns the performance of the workstation, of course "religion" is not the criterion.
>I think there was a time when AMD had a clear upper hand. Some recent benchmarks from Alex convinced me that for the moment i7 is the way to go. It may all change tomorrow.

Comparison of Phenom II X4 and Core i7 shows that intel gives about 10% better performance but these 10% will cost me about 300-400$ more. In some of my older computations (single-core) CPU utilisation was sometimes less than 50%, so it's probably better to spend money on faster HDD or more reliable RAM. Though who knows...