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Generally speaking the reverse is true and the 512GB is faster than the 256GB 2016 MacBook Pro.

However there is always variation, especially because Apple's parts come from different suppliers. For example, many 512GB models are actually slightly faster than 1TB models.

But you can rest assured that any 2016 MacBook Pro in any capacity will have more than enough read/write speeds for your needs! Apple have been industry-leading in disk speeds for some time now.
 
Thank you for the quick response! I am struggling to justify getting a 256GB so I don't have to pay extra for the 512GB. Won't be putting any music or movies on it. Just using it for coding and photoshopping.
 
The speed differences will be un-noticeable in day-to-day use.

From your usage requirements, the 256gb should be fine.
Cheaper, too!
 
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