Processors in that generation relied on a Northbridge device - the [Graphics and] Memory Controller Hub - for access to memory. It is thus this device that determines the memory supported. In this case, the maximum is 8MB (typically 4x 2MB DDR2 DIMMs).
Hope this helps,
Thank you for contacting Intel Customer Support.
The interactive technical support for the Intel® Xeon® Processor X3220 you have requested has been discontinued.
Due to this product being discontinued, Intel Customer Service no longer supports inquiries for it, but perhaps fellow community members have the knowledge to jump in and help.
You may also find the Discontinued Products website (https://www.intel.com/content/www/us/en/support/discontinued-products.html) helpful to address your request.
Thank you for understanding.
Intel Customer Support Technician
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