This is an issue that I have experienced across a considerable number of mid 2015 Macbook Pros (15” with 2.5ghtz processor). I have had several hardware issues with these machines since my initial purchase over a month ago, and in the time since I have had several replacement units that all have the software issue in the description below. Every web browser I have downloaded in addition to the preinstalled Safari browser seems to have noticeably fragmented / glitchy scrolling.. Safari seems to be perfectly capable of loading busy webpages like Facebook or BBC News, and has no problem with me scrolling at medium to high speed through all the posts, photos and videos etc. Chrome and Firefox don’t perform nearly as well and I’m at a loss as to why this is happening. On the first machine I received from Apple, I phoned tech support and the member of the support team I spoke to managed to fix this issue. He took me though the Library in the Finder and asked me to delete a load of unneeded files, like the contents of the caches folder. He then asked me to erase OS and reinstall it, and then everything worked smoothly. Unfortunately this machine had a dead pixel on the screen and I sent it back for replacement. When the replacement had the same software issues, I phoned up tech support again and asked them to take me through what the previous tech support representative had told me to do. When I mentioned reinstalling OS, the new tech support rep advised against this, despite the fact that it had worked the previous time. He claimed that it was my internet connection speed instead, which admittedly was poor – but this didn’t explain why the problem doesn’t occur in Safari, or how the problem had been fixed on my previous macbook despite poor internet speed. Anyway, the second machine also turned out to have a non related hardware issue within the 14 day return period, so I returned this one too. I’ve now bought another machine on which the hardware seems fine, with no physical issues to report – however this glitchy scrolling issue with web browsers is still present. I’ve tried reinstalling OS on this one and had no joy, but I’m fairly certain it’s a software issue now because it doesn’t affect Safari. I think whatever was causing the problem was fixed when the first Apple tech support rep told me delete the contents of certain folders in the Library in Finder. I’m going to try and contact Apple about this at some point, which is difficult as I’m currently in Asia rather than the UK, and I only have a UK mobile number at the moment. Has anyone else had this issue that possibly knows how to solve it? I have a new machine that’s taken me several tries to get it right due to bad quality control on the hardware, and I can’t load any of my stuff onto it as I know I’ll probably end up having to wipe it off and reinstall OS anyway. I’d really like to be able to be able to use it as soon as I can, so any insight/help would be greatly appreciated.