Soldering doesn't do anything about pin count. An off the shelf GPU chip is still going to support at most a PCIe x16 interface to other chips, which isn't enou

Soldering doesn't do anything about pin count. An off the shelf GPU chip is still going to support at most a PCIe x16 interface to other chips, which isn't enough to share DRAM with a separate CPU. Taping out a new chip that combines existing GPU and CPU IP blocks is relatively straightforward, but taping out a large chip is extremely expensive.