Understanding hardware acceleration
Hardware acceleration optimizes a GigaStor active instance for its fastest possible operating speed by using the Gen3 capture card instead of the system CPU.
Hardware acceleration significantly increases the performance of an active instance than without it. By using hardware acceleration with the Gen3 capture card, the fastest capture rates and post-capture analysis can be achieved in your GigaStor hardware or probe appliance. Turning off hardware acceleration is not recommended, as packet capture performance will be greatly degraded because this work is offloaded from Gen3 capture card to the CPU instead where it competes for resources.
Do not turn off hardware acceleration unless you have a specific need to. The feature provides performance benefits only; there are only advantages to gain by using hardware acceleration. However, two situations require that you disable hardware acceleration on the active instance:
1. If you need the GigaStor active instance to filter network traffic in real time using a “deeper” set of filters than the following:
MAC/IP Address
VLAN Tag (802.1Q)
It is a best practice to use the supported broad filters listed or no filters when capturing real-time network traffic with the GigaStor active instance. As soon as the network traffic is written to the RAID array, it becomes available for data mining and more complex filters can be used. If unwanted traffic is entering your GigaStor system, it is instead recommended that the connected switches, SPAN, or aggregator switch be configured to discard those packets before they reach the Gen3 capture card.
2. If you have an eight (8) port Gen3 capture card and intend to create one virtual adapter for each physical port, then hardware acceleration must be disabled. This is because only four virtual adapters can be created while hardware acceleration is enabled. In practice, this is not a typical setup, and better use of your hardware is gained by leaving hardware acceleration enabled than separating more than four ports of traffic.
Tip! You can verify if hardware acceleration is enabled by viewing the capture card properties.
The active instance is the only probe instance that can be configured for hardware acceleration. This means you cannot configure a passive instance to use hardware acceleration—the option simply does not exist—but passive instances can always be created from your hardware-accelerated active instance. Each GigaStor appliance with a Gen3 capture card is configured to use the card for the active instance, so the best capture performance is ready out-of-the-box.
Hardware acceleration does not affect or speed-up statistics-based features like Network Trending. Statistic-based features behave exactly the same whether hardware acceleration is enabled or disabled, and this is because hardware acceleration affects packet capture modes only.
Note: When allocating memory for any probe instance with the VIAVI capture card as the chosen adapter, at least 80 MB of memory must be allocated to both the capture buffer and statistics queue buffers. Failure to do so will result in the inability to capture data. This must also be followed for any Gen3 capture card that has hardware acceleration enabled.