Webapi (.NET Core) has no performance gain when using async

Question

I’m implementing an asynchronous api, but I haven’t seen much performance gain. I used Restful Stress for Chrome to do my tests, I simply didn’t see performance gain when using async. I thought this would increase the number of simultaneous requests.

Configuration used Result using async Result without using async Code using async

public async Task<ObjectResult> Get()
{
    try
    {
        //usando ToListAsync() a performance foi pior, por isso usei Task
        //var result = await _dbSet.AsNoTracking().ToListAsync();
        var result = await Task.FromResult(_dbSet.AsNoTracking().ToList());

        return Ok(result);
    }
    catch (Exception ex)
    {
        return this.BadRequest("ERROR: " + ex.Message);
    }
}

Code without using async

public ObjectResult Get()
{
    try
    {
        var result = _dbSet.AsNoTracking().ToList();

        return Ok(result);
    }
    catch (Exception ex)
    {
        return this.BadRequest("ERROR: " + ex.Message);
    }
}