It seems to me that the wireless features of both the DIR-855 and DIR-655 are pretty much the same. The only exception is that DIR-855 came equipped with 5Ghz Wireless A/N band.
I remember being taught that the higher the frequency, the shorter the wavelength but higher penetrative strength. Shorter wavelength leads to shorter transmission distance. So I would expect wireless network on 5Ghz band to be shorter in range but packs more punching power through walls or obstacles. I’ve done a simple wireless speed test without any obstacles in this post (DIR-855 wireless speed).
So what are the obstacles in this test? The laptop is in the kitchen while the DIR-855 is in the living room. I would estimate that they are like 10 meters apart. In the middle are 2 walls and 1 LCD TV as depicted in the picture below.
Placement of the DIR-855 and laptop
- DIR-855 (firmware 1.12WW)
- DIR-655 (firmware 1.21)
- ReadyNAS Duo
- HP EliteBook 2530p (Broadcom 4322AG wireless module)
How are the tests like
This test involves wireless transfers off my network storages (DNS-323, DNS-343, ReadyNAS Duo) on the 2.4Ghz and 5Ghz band of the wireless network. In the first test, DIR-655 is used as a baseline. This is to check whether the DIR-855 offers any improvement in wireless coverage.
Do take note that firmware plays a part in the performance.
In this test, the router and laptop are approximately 6 meters apart. In between them are:
- a LCD TV on a wooden TV shelve
- wooden door
- stack of magazines
The objective is to find out if the wireless signals are able to punch through the obstacles and reach my laptop.
Wireless distance test on the DIR-655
In the wireless distance test, the DIR-655 performed well with the following result:
Download speed of 86.2 Mbps through 2.4Ghz wireless in mixed mode (b/g/n)
Close to the speed of a typical 100 Mbps wired!
Wireless distance test on the DIR-855
The design of the DIR-855 is similar to the DIR-655 – 3 antennas. Wonder how does it perform in the wireless obstacles test? 2 tests were conducted – one on the 2.4Ghz band, one on the 5Ghz band.
Download speed of 91.6 Mbps through 2.4Ghz wireless in mixed mode (b/g/n)
Seems like there is a marginal improvement on the transfer speed on the 2.4Ghz band. How about the test on 5Ghz band?
Download speed of 35.1 Mbps through wireless N (5Ghz)
Seems like the speed suffered quite a fair bit due to the distance.
Wireless obstacles test on the DIR-655
Download speed of 77.8 Mbps through wireless N (2.4Ghz)
DIR-655 clocked 77.8 Mbps in the wireless test. It seems like wireless congestion has impacted the stability of the transfers. Wonder how would the DIR-855 perform?
Wireless obstacles test on the DIR-855
Download speed of 100.8 Mbps through wireless N (2.4Ghz)
DIR-855 has clocked 100.8 Mbps in this test on the 2.4Ghz band! A rather significant speed boost in my opinion. Stability of the transfer is still an issue. Seems like it packs more power than the DIR-655.
Download speed of 83.4 Mbps through wireless N (5Ghz)
The transfer is more stable compared to the 2.4Ghz band.
From the test results, it seems like file transfers on the 2.4Ghz band is like taking a roller coaster ride, going up and down every now and then. This is probably due to the wireless congestion around my area.
5Ghz band offered much more stability for the transfers which preferable for time sensitive information transfers like streaming videos to your network media player.
Although the transfers are much more stable, the throughput rate on the 5Ghz band is halved at the distance I performed the test. It is pretty inline with the basics of engineering (frequency = inverse of wavelength). Hence, the impact of distance on sustainable transfer speed is much more visible on the 5Ghz band than 2.4Ghz band.
According to the basics, higher frequency would also have higher penetrative strength. The results shows otherwise for the test on 2.4Ghz and 5Ghz band. However, it can be observed that DIR-855 packs more punch than the DIR-655 on the 2.4Ghz band as DIR-855 managed to achieve 100.8 Mbps while DIR-655 got 77.8 Mbps. It is also observed that DIR-855 on 5Ghz band offers higher wireless throughput and better transfer stability than the DIR-655 (2.4Ghz).
- DIR-855 offers higher wireless throughput than the DIR-655 on wireless N (2.4Ghz)
- DIR-855 offers higher wireless throughput and transfer stability than DIR-655 when DIR-855 is on the 5Ghz band
- DIR-855 offers lower wireless throughput but higher transfer stability than DIR-655 at longer distances