31 July 2019

Ryzen 5 2600 Browser Latency

I have recently built my first Ryzen desktop. I am running the Ryzen 5 2600 processor with 32GB RAM, the Sapphire Radeon Pulse RX 580 8GB graphics card, and a couple of SSDs.

My goal was to get system which could handle the output of one 4K monitor and an HD second monitor without any sluggishness. The graphics card seems to be meeting this goal. The 32GB RAM also helps keep the machine spiffy.

What I am finding, though, is that at times when choosing functionality within a website, operations for that activity pauses for a moment or two. Simple actions such as opening a page from a bookmark or pulling a list for a dropbox are met with the same pause. It's more than data retrieval on the backend. The all browser interaction is suspended.

I do see a spike for the browser process in my system monitor, but I've seen that on Intel processors running under the same or lesser load with no latency. The spike happens, but there is no lag with Intel. And the Intel boxes do not have the graphics horsepower or increased memory this Ryzen box has.

And it is not just a single browser. I have seen this behavior with four different browsers on the same system. Is this just a Ryzen thing?

I want to blame Javascript because we all know how much of a glutton for memory it is. But it is more than just a single page or tab within the browser. I cannot immediately switch among my tabs during that pause. Maybe it really is Javascript impacting the whole browser. I have not done any investigation to determine if that is the case.

If it is the Ryzen chip, maybe the Ryzen 5 2600X might perform better. Overall, I am pleased with Ryzen and would like to do more with it. This is the only real issue I have encountered.

24 July 2019

NMAP Adventures

Today, I spent some time checking some firewall rules to see if any were still valid and which ones could be cleaned up. (These are internal firewall rules between our cloud account and our data center.) I was using nmap.

At a point, I wanted to be able to check both TCP and UDP protocols for a specific port for a specific host. I read through the help and man pages to see that I can use -sO. This is where things got a little wonky. (Number have been changed to protect the innocent.)

$ nmap -sO 1-17 -p 52001 10.10.10.5
Starting Nmap 7.70 ( https://nmap.org ) at 2019-07-24 13:16 EDT
Protocols specified must be between 0 and 255 inclusive
QUITTING!

Huh?

$ nmap -sO 1,6,17 -p 52001 10.10.10.5
Starting Nmap 7.70 ( https://nmap.org ) at 2019-07-24 13:16 EDT
Protocols specified must be between 0 and 255 inclusive
QUITTING!

This goes on for a little longer using different syntax. I dig further into the man page. After hashing it out, this sentence reveals the confusion:

Yet it still uses the -p option to select scanned protocol numbers, reports its results within the normal port table format, and even uses the same underlying scan engine as the true port scanning methods. So it is close enough to a port scan that it belongs here.

Wait, so, the -p option is used differently than everywhere else? Seems like it. I feel like points should be deducted here.

Using the following gets me the list of my protocols, however they are not completely what I need to know:

$ nmap -sO 10.10.10.5 -p 1,6,17
Starting Nmap 7.70 ( https://nmap.org ) at 2019-07-24 14:06 EDT
Nmap scan report for 10.69.55.214
Host is up (0.00086s latency).

PROTOCOL STATE         SERVICE
1        open          icmp
6        open|filtered tcp
17       open          udp

Nmap done: 1 IP address (1 host up) scanned in 1.48 seconds

Here's the real truth, though:

$ nmap -sU -sT -p 52001 10.10.10.5
Starting Nmap 7.70 ( https://nmap.org ) at 2019-07-24 13:32 EDT
Nmap scan report for 10.69.55.214
Host is up (0.00081s latency).

PORT      STATE  SERVICE
52001/tcp open   unknown
52001/udp closed unknown

Nmap done: 1 IP address (1 host up) scanned in 0.49 seconds

And it leads me to this final bit of confusion: Why does the scan using -sT -sU -p 52001 not give me the same as using the -p U:52001,T:52001 syntax? This is what the latter gives me:

$ nmap -p U:52001,T:52001 10.10.10.5
Starting Nmap 7.70 ( https://nmap.org ) at 2019-07-24 14:06 EDT
Nmap scan report for 10.69.55.214
Host is up (0.00084s latency).

PORT      STATE SERVICE
52001/tcp open  unknown

Nmap done: 1 IP address (1 host up) scanned in 0.49 seconds

This is very confusing. Comment if you have some insight into this.