3 Replies Latest reply on May 12, 2011 8:56 PM by

    PCI performance issue with memory read on modern motherboard

    vitalyn

      I'm hardware and software developer. Two years ago i'v developed PCI card. It reads data from RAM as Bus Master and transfers it to other hardware. For one task it is required to read 48 packs of data (6 words per pack, 32 bits per word). It is very important how many tasks per second can be performerd. 

       

      We used different motherbords. Best result was achieved on ASUS M2N motherboard - more then 20 000 tasks per second (20 kHz). It is good result but now this model is not available Also we've used Mini-ITX Intel D945GCLF2D motherboards - about 11 kHz. Bad. I've tested ASUS M4A88T-M - performance is 9.45 kHz. Very bad.

       

      I've investigated this problem with oscilloscope. Approximately half of  transaction aborted by #STOP immediately after Memory Read command cycle.

       

      Software runs under Linux. System has 2 GB of memory - 1GB is dedicated for use by my software and PCI board, other 1 GB is left for use by Linux. Software prepares data and puts them in dedicated memory. When all data is prepared and placed in RAM software starts PCI card to work. It works in Bus Mastering mode (DMA). When PCI card works it is nothing to do by software.

       

      I've tried to install different number of memory modules, change all settings in BIOS setup... Nothing helps.

       

      What modern motherboard can I use? I need good PCI performance (read from RAM) and 1GbE LAN. Mini-ITX preferred.

        • 2. Re: PCI performance issue with memory read on modern motherboard
          vitalyn

          AMD Athlon X2 2.6 GHz on ASUS M2N SLI with DDR2 memory (2x1G) (best performance achieved - more than 20 kHz)

          AMD Athlon II X2 3.1 GHz on ASUS M4A88T-M with DDR3 (2x2G) (9.45 kHz)

          Intel Atom 1 GHz on D945GCLF2D with DDR2 (2x1G) (11 kHz)

          Also i've tested some motherboard with i5 processor at 3.0 GHz (9.7 kHz).

          • 3. Re: PCI performance issue with memory read on modern motherboard

            Table with results of several motherboards tests:

             

            MSI PH67A-C43 + i5-2400 3.1 GHz - 5,70 kHz

            ASUS   P8H61 + i5-2400 3.1 GHz - 5,70 kHz

            ASUS P8H61 + i7-2600 3.4 GHz - 5,70 kHz

            Gigabyte GA-HA65M-D2H-B3 + i5-2400 3.1 GHz - 6,98 kHz

            ASUS M4A78LT-M LE + Athlon II X4 640 3.0 GHz - 9,31 kHz

            MSI 790FX-GD70 + Phenom II X3 720 2.8 GHz - 9,49 kHz

            ASUS M4A77T-M + Athlon II X4 640 3.0 GHz - 9,50 kHz

            ASUS   M4A88T-M + Athlon II X2 3.1 GHz = 9,52 kHz

            Intel   CPU-D510MO(B) + Atom D510 1.66 GHz - 11,60 kHz

            ASUS   M4N78-AM V2 + Athlon 64 3500+ 2.2 GHz - 12,10 kHz

            ASUS   M4N72-E + Athlon 64 X2 Dual Core 5600+ 2,9 GHz - 12,13 kHz

            Gigabyte   M68MT-S2 + Athlon II X2 3.1 GHz - 13,54 kHz

            ASUS   M4N68T V2 + Athlon II X2 3.1 GHz - 13,54 kHz

            ASUS   P5K-VM + Core 2 1.8 GHz - 13,62 kHz

            Intel   D945GCLF2D + Atom 1 GHz - 13,76 kHz

            Gigabyte   GA-P55-UD3L + i5 2.8 GHz - 13,76 kHz

            ASUS   P5G41T-M LX2/GB + Pentium DualCore E5200 2.5 GHz - 13,79 kHz

            ASUS   P7P55-M + i7 860 2.8 GHz - 13,84 kHz

            ASUS   SABERTOOTH X58 + i7 960 3,2 GHz - 13,90 kHz

            ASUS   M2NPV-MX + Athlon 64 3000+ 1.8 GHz - 14,57 kHz

            Gigabyte   GA-6VMML + –°eleron 500 MHz - 16,04 kHz

            Intel   D845EPI/D845GVSR + –°eleron 2.0 GHz - 16,79 kHz

            ASUS   M2N-SLI + Athlon 64 X2 Dual Core 2,6 GHz - 20,22 kHz

            ASUS   M2N-SLI + Athlon 64 X2 Dual Core 6000+ 3.0 GHz - 20,22 kHz