Hi guys, I have a Dell Inspiron 15 5577 gaming laptop with GTX 1050 and want to connect it with an external monitor. Since it's my secondary laptop I'm planning to convert into an entry-level gaming machine. I mostly play competitive games like CS:GO. I know displays with TN panel will be best for this kind of use case but I'm confused if I'll be able to get better performance with HDMI. Can I use monitors with DisplayPort on this laptop? Also, can it support a 120hz monitor with resolutions higher than 1920*1080?
This system's GPU is decidedly below the current entry level for gaming - it's just not going to be a decent performer with a high resolution external monitor. If you disable the internal screen and go with an FHD external monitor it should do about as well as with the internal - any more than that and you'll find it lagging.
I don’t see an Inspiron laptop with the 7555 model designation. Might want to recheck that. Unless one of those outputs is wired directly to the NVIDIA GPU rather than the more common design of all outputs being wired to the Intel GPU, then DisplayPort and HDMI will perform identically up to the resolutions they both support. It’s possible that HDMI on that system would be limited to 2560x1600 while DisplayPort typically goes to 4K (assuming 60 Hz in both cases), but again without knowing the model you actually have, it’s tough to say. Same goes for 120 Hz support, especially above 1080p.
My bad!!! Edited the model number now, it's Dell Inspiron 15 5577 gaming laptop with Intel i7-7700HQ 2.8GHz 16Gb Memory and GTX 1050. Will this help now?
Ok, according to the Inspiron 5577's Setup and Specifications document on support.dell.com, that system doesn't have a DisplayPort output at all. All you have is HDMI, so that sort of settles that. The specs don't specify the version of HDMI it supports, which means it's very likely just HDMI 1.4 rather than 2.0. From a bandwidth perspective, that would be enough to run 2560x1600 at 60 Hz or 1920x1200 at 120 Hz, but that doesn't by itself mean you can actually run 120 Hz. On that front, if you have access to some sort of HDMI display/TV, try connecting it and opening NVIDIA Control Panel. Somewhere in there it should indicate whether that HDMI output is physically wired to the Intel GPU or directly to the NVIDIA GPU. If it's the NVIDIA GPU, then you should be fine (although as ejn63 said, actually achieving 1080p at 120 fps is probably ambitious anyway), but if it's wired to the Intel GPU, I'm not sure that any Intel GPUs support 120 Hz yet, but I admittedly haven't looked into it.