What are the rest of the system's specs? Is the RAM maxed out?
Killing the power management is absolutely step #1 (it causes nothing but issues on a realtime DAW PC - that's not the place to try and conserve power
). Your ASIO driver may run better if "Processor Scheduling" is set to "Background Services" (more of a throwback to XP, but can help under W7, too).
How is your system's DPC latency? You can check it with this utility:
http://www.thesycon.de/deu/latency_check.shtmlIf you get any yellow or red spikes, you'll need to find out what driver in your system is causing issues and address it. Generaly WiFi/LAN and Video drivers can be very common culprits. A well-behaved system will average around 30-80us, and NEVER spike much higher than 100us.
And of course playing with the Firewire controller's driver (assuming this is a firewire version - didn't specify the model of Sapphire) can also do wonders with regard to the audio interface's performance (I only use PCI/PCIe myself, so I can't speak from first hand experience, but tons of people have reported improvements from using an older Firewire Controller Driver under W7).
If this is a USB interface - try to disable all USB Power Savings for all USB Hubs in the Device Manager - and maybe try with and w/o a USB Hub for grins.
I'd agree that the ASIO-4-All should generally not be used if the native ASIO driver is worth a darn unless you need to aggregate drivers under ASIO in Windows (still not generaly recommended for absolue best performance).
And sorry to say this, but Focusrite isn't exactly known for their extremely efficient drivers:
http://www.dawbench.com/audio-int-lowlatency.htmI'm sure you can get it to be useable "as-is", but there will be an improvement by going to a more efficient card with top-notch drivers. Getting the laptop up to snuff (weeding out all potential issues) will likely be sufficient with your current interface IMO...
Good luck!