Apple Mac Pro ME253LL/A - 3.7 GHz Quad Core Xeon - 48 GB RAM - A148 - MacPro6,1

Description

I am the original owner of this Apple Mac Pro.
Apple Mac Pro only been used for home use (not a business machine like many others).
Apple Mac Pro "Quad Core" 3.7 (Late 2013)
Identifiers: Late 2013 - ME253LL/A - MacPro6,1 - A1481 - 2630
Processor Speed: 3.7 GHz
Turbo Boost: 3.9 GHz
The 64-bit 22-nm "Xeon E5" processor, or more specifically the "Ivy Bridge-EP" based E5-1620v2, has four independent "cores" each with a dedicated 256k level 2 cache and 10 MB of level 3 "Smart Cache." It also supports "Hyper-Threading" -- which "allows two threads to run simultaneously on each core" (so OS X recognizes eight total cores on this model, four real and four virtual) -- and "Turbo Boost" -- which "automatically boosts the processor speed based on workload" up to 3.9 GHz for this model.
RAM: 48 GB (3x 16 1866MHz DDR3 ECC-R SDRAM, ECC Registered)
Video Card: AMD FirePro D300 x2
Dual AMD FirePro D300 graphics processors with 2 GB of GDDR5 memory eachCrossfire X can be enabled when using this as a Windows system.
Connectivity: Connectivity includes six Thunderbolt 2 ports, one HDMI 1.4 UltraHD port, 4 USB 3.0 ports, and Dual Gigabit Ethernet ports in addition to 802.11ac and Bluetooth 4.0.
The Thunderbolt 2 ports can connect to Display Port monitors via properly certified mini display port plugs.
Storage: 256 GB SSD (PCIe 2.0 x4 flash storage)
Wifi: 802.11ac
Bluetooth: 4.0
Apple Model No: A1481 (EMC 2630)
Model ID: MacPro6,1
Upgraded the RAM with an OWC kit in 2019.
Will ship with clean installation of Big Sur.
Works fine, with exception of 4th RAM slot. The 4th RAM slot is unresponsive, this ships with 3x16 GB RAM modules for total of 48 GB of RAM.