Three-dimensional (3D) DRAM integrated in the same package as compute logic enable forming high-density caches. In one example, an integrated 3D DRAM includes a large on-de cache (such as a level 4 (L4) cache), a large on-die memory-side cache, or both an L4 cache and a memory-side cache. One or more tag caches cache recently accessed tags from the L4 cache, the memory-side cache, or both. A cache controller in the compute logic is to receive a request from one of the processor cores to access an address and compare tags in the tag cache with the address. In response to a hit in the tag cache, the cache controller accesses data from the cache at a location indicated by an entry in the tag cache, without performing a tag lookup in the cache.