http://processorfinder.intel.com/Details.aspx?sSpec=SL7YV
http://processorfinder.intel.com/details.aspx?sSpec=SL8J9
The 515 has a bus/core ratio of 22
The 516 has a bus/core ratio of 21.8
Bus/Core Ratio: The ratio of the system bus speed and the operating (core) frequency of the processor. This information is needed by most motherboards when setting up the BIOS for a new processor.
The 515 has a VID voltage range of 1.25V - 1.388V
The 516 has a VID voltage range of 1.25V - 1.400V
VID Voltage Range: The voltage range set by the VID signals as a reference to the VR output voltage to be delivered to the processor Vcc pins.
The 515 has these supported features
# Enhanced Halt State (C1E)
# Execute Disable Bit 1
# Intel® Thermal Monitor 2
The 516 has these supported features
# Intel® EM64T 1
# Enhanced Halt State (C1E)
# Execute Disable Bit 2
# Intel® Thermal Monitor 2
Intel® EM64T (516) requires a computer system with a processor, chipset, BIOS, operating system, device drivers and applications enabled for Intel EM64T. Processor will not operate (including 32-bit operation) without an Intel EM64T-enabled BIOS. Performance will vary depending on your hardware and software configurations. See http://www.intel.com/info/em64t for more information including details on which processors support Intel® EM64T or consult with your system vendor for more information.
Intel® 64 architecture delivers 64-bit computing on server, workstation, desktop and mobile platforms when combined with supporting software.¹ Intel 64 architecture improves performance by allowing systems to address more than 4 GB of both virtual and physical memory.
Intel® 64 provides support for:
* 64-bit flat virtual address space
* 64-bit pointers
* 64-bit wide general purpose registers
* 64-bit integer support
* Up to one terabyte (TB) of platform address space
Hope this helps...
Good luck...
Peccavi
October 2009