https://www.dell.com/support/product-details/en-us/product/oth-r820/drivers
Support for OEMR R820 | Drivers & Downloads | Dell US
Get drivers and downloads for your OEMR R820. Download and install the latest drivers, firmware and software for Windows devices.
support fordrivers downloadsdellus
https://www.spec.org/cpu2006/results/res2012q2/cpu2006-20120522-22066.html
CINT2006 Result: Dell Inc. PowerEdge R820 (Intel Xeon E5-4610, 2.40 GHz)
CINT2006 result for PowerEdge R820 (Intel Xeon E5-4610, 2.40 GHz); base: 841; peak: 878