Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Chip | Flash size | EEPROM | SRAM | Frequency\n[MHz] | Package |
| --- | --- | --- | --- | --- | --- |
| AT90S1200 | 1k | 64 | 0 | 12 | PDIP-20 |
| AT90S2313 | 2k | 128 | 128 | 10 | PDIP-20 |
| AT90S/LS2323 | 2k | 128 | 128 | 10 | PDIP-8 |
| AT90S/LS2343 | 2k | 128 | 128 | 10 | PDIP-8 |
| AT90S4414 | 4k | 256 | 256 | 8 | PDIP-40 |
| AT90S/LS4434 | 4k | 256 | 256 | 8 | PDIP-40 |
| AT90S8515 | 8k | 512 | 512 | 8 | PDIP-40 |
| AT90S/LS8535 | 8k | 512 | 512 | 8 | PDIP-40 |
Question:
what is the flash size difference in the at90s8515 chip and the at90s4414?
Answer:
4k