SSD 1 tb no Vostro 3550

Compre seu ssd com a capacidade que lhe atenda, essa limitação não existe, a dell apenas indica o que foi homologado por eles.

A época do lançamento desse modelo, 2011, o comum era ssds de 120 ou 240gb. Poucos usavam capacidade acima disso.

Você pode ainda comprar um case para transformar o HD original em HD externo.

OBS: meu irmão teve um Vostro 3550 por 9 anos, de 2011 a 2020.

You may safely use any 2.5" SATA SSD. If you want, you could go all the way to 4 TB.

I have a Dell XPS L502x, same 2nd-generation as your Vostro, same year 2011. I installed a 1 TB SSD and it works well.

There is other work that you should do. At 12 years old, the thermal compound has dried out and cannot adequately transfer heat away from the processor, and there may be a lot of dust inside the laptop and maybe inside the fan and heat fins. So, your laptop is unable to adequately cool itself and your processor may throttle and reduce its speed.

You might consider an internal cleaning. Open it up to clean out dust. Disassemble the fan to clean out dust and fluff. I found a fair bit in two laptops I worked on recently. Remove the heat sink, remove the old thermal compound and apply new thermal compound before reinstalling the heat sink.

While you're in there, replace the CMOS battery. If it isn't dead, it soon will be. BIOS settings and date/time can't be saved without a functioning CMOS battery.

Follow the disassembly and reassembly steps in Dell's Owner's Manual.

Look on YouTube for videos showing disassembly of your model. But, be cautious with them, as some use steps or methods that are not appropriate. Use the videos to add to your understanding of what to do, but follow the steps in Dell's manual.

Whenever touching components or working inside a computer, wear a grounded wrist strap, also called anti-static wrist strap, ESD wrist strap, or ground bracelet. It's a cheap and sensible precaution. Rest the laptop on an anti-static mat or at least a reasonable alternative such as corrugated cardboard.