No, a 4bit RAM IC won't typically cause issues with overclocking.
No, a 4bit RAM IC won't typically cause issues with overclocking.
Recently I purchased two packs of DDR4 RAM from G.skill, intended for bulk use rather than high speed. To save money, I opted for the Aegis Series model with ID F4-3200c16D-32GIS. After testing Thaipoon, it wasn't clear which die variant was used, so I examined the memory IC and found it reads k4a8g045wb-bctd. This indicates a 4-bit B-die with a BCTD variant, not the optimal B-die. Likely this is why it's labeled at 3200c16 instead of 3200c14. The exciting part is that these RAM sticks are designed for 8GB density with 2GB per die, yet each stick holds 16GB. It seems G.skill chose a 4-bit memory IC rather than the standard 8-bit one (which should correspond to k4a8g085wb-bctd, as seen on other brands). They apparently crafted something unusual to meet the market need for 16GB per stick.
BTW 4bit chips are commonly found in ECC/RECC server RAM modules and aren't meant for regular consumer applications.
It's unclear if a 4-bit RAM IC shares the same overclocking capabilities as an 8-bit IC.
The issue with DIMMs featuring a 4-bit interface on them is that the connections between packages become less impedance-matched compared to standard 8-bit DRAM. I own some dual-rank 4800MHz 4-bit DRAM packages rated for overclocking, but I can't reliably push past 6000MHz effectively.