Question laptop getting slow internet speed as compared to other devices

Apr 1, 2019
So my isp provide 50mbps download and 50mbps upload speed.But on my laptop i get only 20 mbps download and 30 mbps upload when connected my laptop to wifi though i get 50mps both upload and download when i connect my phone using same wifi network . ichecked on my friend's laptop and he ws also getting 50mbps speed his laptop is of dell i3 and maybe a 2013 model mine's is lenovo core2duo maybe 2009-2010 model and my phone is also lenovo 2015 model can someone please tell me . my mode in wifi router is 11bg and 11bgn(mixed) i have choosed 11bgn(mixed) when i connect my inernet wire direct from isp to my laptop it doesn't connect but when i connect it to wifi router and use lan port of wifi router then it connects to my laptop(imean lan port cable from wifi router connects to my laptop) also the direct wire from isp connect to my friends laptop without wifi router