what type of ram (memory) is this?
what type of ram (memory) is this?
They look messy, but overall fine, considering the small chip, definitely ECC.
I don't believe the middle chip is intended for ECC. It seems more likely a serialization component like registered RAM or a memory banking IC. You can also observe all DATA traces flowing through that central chip rather than individual RAM chips. This suggests the center chip interacts with the side and opposite RAM modules. Given only one notch, it probably points to a DDR1 or DDR2 module.
fully buffered DDR2 modules resemble your existing sticks. The central chip handles the fully buffered function, retrieves bits from the chips and sends them to the data pins. Links provided show examples: Apple Mac Pro 2006-2008 DDR2 PC2 667MHZ, Dell ECC DDR2 Server Memory.
I checked the details for the chip HYB18T512 800af3s from Infineon. It appears to be a 512MB memory module, but I wasn't sure if there were any recent searches about it.
It's feasible ... HYB18T512 equals 512 Mbit (64 MB RAM chip) ... 245085_DS.pdf contains 9 RAM chips, each 512 Mbit, totaling 8 x 512 = 4 GBit plus ECC (512 MB DDR2 sticks)