According to Strategic Test, there are two distinct advantages to 64-bit Windows over 32-bit. In the first case, 64-bit Windows delivers a higher computation performance that is a particular benefit to engineers and scientists who undertake real-time analysis of measurement data or signal processing. Secondly, 64-bit Windows supports up to 128 GigaByte of PC RAM compared to the 4 GBytes of 32-bit Windows XP. This means that if the Digitizer or AWG card supports streaming, the signal data to/from the host-PC RAM and the total recording/replay rate is lower than the data transfer bandwidth of the PCI bus used, then the engineer can use the low-cost PC-memory instead of buying expensive instrument memory. This method also allows longer recording/replay times, as the maximum amount of signal memory that can be added to the current range of Digitizer or AWG cards from most vendors is 4 GBytes.
To illustrate this further. A Digitizer card with two 100 MS/s 8-bit A/D channels will quantize the signals at a rate of 200 MBytes/second. In order for this data to be transferred continuously and gap-free to the host-PC memory, the PCI bus would need to support this data transfer rate. Assuming that the card is based on the 66 MHz / 32-bit PCI bus (also known as PCI-X) that is available on newer products, this bus supports continuous data transfer rates of up to 225 MBytes per second and therefore can be used to stream the data in this example. Using 32-bit Windows XP Pro, the maximum measurement time would be limited by the 3.5 GB useable memory giving a maximum time of 17.5 seconds. However, on a PC configured with 128 GB RAM running 64-bit Windows XP Pro, the measurement time would increase to over 6.5 minutes.
The Windows XP Pro x64 driver is supplied at no cost and can be downloaded by existing customers from the company website. The same simple programming concept found in the other Windows and Linux drivers has been employed, allowing customers to upgrade their OS without modifying their application code.
