Intel verified that there will only be four Arc "Alchemist" desktop graphics card SKUs in the retail channel, directed by the A770 Limited Edition (reference card), which maxes out the DG2-512 silicon. 

That card now is get 17.5 Gbps memory across its 256-bit wide memory bus, giving it 560 GB/s of memory bandwidth. The A750 features 512 GB/s of bandwidth and 16 Gbps memory data speeds. The mid-range A580, it turns out, has a 256-bit wide memory bus rather than the previously stated 192-bit, which implies it offers the same 512 GB/s bandwidth as the A750. The A580 and A750 have 8 GB of memory, while the A770 has 16 GB.

The Arc A770 will be Intel's top-of-the-line model, with 32 Xe cores (equivalent to 4,096 stream processors) running at 2,100 MHz and coupled with 8GB or 16GB of GDDR6 memory with a peak bandwidth of 560 GBps. The Arc A750 will be priced somewhat lower than the flagship and will have a scaled-down ACM-G10 GPU with 28 Xe cores (equivalent to 3,584 shading units) operating at 2,050 MHz and linked to 8GB of GDDR6 memory with a peak bandwidth of 512 GBps. Both cards might be considered among the finest graphics cards if they function perfectly, give enough performance, and are reasonably priced.

The higher-end model "Arc A750" has 28 Xe cores, 28 ray tracing units, 448 XMX engines, a core frequency of 2,050 MHz, a memory bandwidth of 512 Gbps, and an 8 GB GDDR6 visual memory.

The middle-tier model "Arc A580" has 24 Xe cores, 24 ray tracing units, 384 XMX engines, a core speed of 1,700 MHz, a memory bandwidth of 512 Gbps, and 8 GB of GDDR6 visual memory.

The entry-level "Arc A380" includes 8 Xe cores, 8 ray tracing units, 128 XMX engines, a core speed of 2,000 MHz, a memory bandwidth of 186 Gbps, and 6 GB of GDDR6 visual memory. 

  Intel Arc Alchemist Specifications

Intel Arc A770 To Feature 17.5 Gbps Memory - Intel Reveals Specifications