The sizes are different. This may be due to different internal ECC data organizations.
The GD5F1GQ5UEYIG (
datasheet) can be used with or without internal ECC:
whereas the F50L1G41LB (
datasheet) seems to have a fixed ECC size:
Try to read the GD5F1GQ5UEYIG with the setting for page size = 2048 Byte +64 Byte. Then the data should match the size of the F50L1G41LB.
Next make sure the devices are operated at their correct supply voltages.
The GD5F1GQ5UEYIG can operate from as low as 1.8 V:
whereas the F50L1G41LB requires 3.3 V:
And check the clock frequency. Assuming the device is operated at 3.3 V ( a prerequisite for replacing the GD5F1GQ5UEYIG by the F50L1G41LB, see above), the GD5F1GQ5UEYIG can operate at up to 133 MHz:
whereas the F50L1G41LB reaches only 104 MHz: