Intel Quad-core Core i7 940 2.93 GHz, Asus P6T-Deluxe Mainboard, 6x2GB (triple channel) DDR3-1333 RAM@1333 MHz, four Seagate 1 TB SATA-2 ST31000340NS HDDs, Windows Server 2008 Enterprise x64. Hyperthreading and Turbo Boost Technology were enabled in BIOS.

Test 1, single-point direct DFT (B3LYP) energy plus gradient for medium-size system (623 basis functions). View image

Test 2, single-point semiempirical (PM3) energy plus gradient for large system (540 atoms, 2160 basis functions). View image

Test 3, single-point direct MP2 energy for medium-size system (623 basis functions, the same system as one used for Test 1). View image

Test 4, single-point two-state MCQDPT2 energy with ISA energy denominators shift for small model system. View image

Test 5, single-point direct CASSCF(12,12) for medium-size system (retinal molecule, cc-pVDZ, 565 Cartesian basis functions) using ALDET code. View image

Test 6, single-point direct CIS energy plus gradient of first excited state of medium-size system (porphyrin molecule, cc-pVTZ (aug-cc on Nitrogens), 1130 Cartesian basis functions, D_2h group). View image

Tests 2, 4, as well as standard MCQDPT2 and MP4 benchmarks were run in multithreaded mode, other tests were run in standard parallel mode using dynamic load balancing over p2p interface. MPI: Intel MPI version 3.1 using mpiexec.exe -genv I_MPI_WAIT_MODE 1 settings. Unless explicitly stated otherwise, all multithreaded benchmarks used only single logical processor of each allotted CPU core. Call64 switch was turned on for all tests for faster processing. Note that test 2 does not scale well mainly due to limitations of the PC GAMESS' semiempirical code, while test 4 would scale much better for larger job. Test 5 is the most memory and communications intensive one. Test 2 and MP4(SDTQ) benchmark are mainly dgemm-limited and thus do not benefit from the use of HTT. CPU or Wall clock times are given on master node in seconds.

Note, the data on scalability above are not quite accurate, as all the tests running using only single CPU core were executed at higher CPU clockspeed (3.2 GHz due to Turbo Boost) than those using two or more CPU cores (2.93 GHz). For accurate data, see this link