Camera Labs

I just made the strange observation, that my scanner and scan-software slowed considerably down, when my anti-virus (AV) software was on. With "on" I don't mean actively screening/scanning my hard-disks but just sitting there, waiting for "things" to happen. This is the normal status my AV-software is in so I expected nothing remarkable, when I scanned some newspaper pages. But after the first page or so I noticed, that the transfer of the scanned page to the computer took longer than the scan itself. So I had to wait after I already turned to the next page before hitting the scan-button again as the previous scan was still loading. Hmmm...
I don't know how I found out, but as soon as I switched my AV-software off, file-transfer from the scanner (via USB) to the hard-disk was up to the old speed again.

So today, before scanning multiple pages, I turn the AV-software off.

Now the big Q is: What was the AV-software doing? Was it analysing the data-stream coming from the scanner to the hard-disk? Was it so busy analysing the last scan-file that the performance of the disk took a hit and it could not collect the incoming bits of the next scan-stream fast enough? We are talking about 1-2MByte per page at around 8 seconds on a Core 2 Duo 3 GHz system with 3 Gig RAM and all 7200rpm SATA300 drives. So this was hardly a real challenge.

So my question goes out to you:
- Did you ever encounter similar effects from your AV-software on system performance when handling/creating large files?
- Specifically for those who edit video footage and render large files: Have you experienced an increase in performance when deactivating the AV-software?
- Which AV-software did you use then? Mine is Trend Micro PC-cillin.

----
17 to go...

_________________
Thomas (beware: Nikon-fanboy and moderator!) My Lens Reviews, My Pictures, My Photography Blog
D800+assorted lenses

Hi Thomas,

I see something that may be related if I download large zip files. The download proceeds at a normal speed (as shown by Firefox's progress indicator) but then, just as you think the download is finished, there is a significant pause before the file download "completes" while Kaspersky scans the contents.

Bob.

175 to go...

_________________
OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.

alls i know is my comp takes a good 20secs longer to startup because of McAfee....

I use Esset NOD32 and i'm verry happy for the way it's working. i don't have the feelling it's consuming too many resources, and with the viruses signature updated at day, my 1.5years (maybe older) win xp instalation is virus free. I recommend it to every one of you who wish a good AV.

Cheers,
HNV

_________________
"Make things as simple as possible, but no simpler." Albert Einstein

most security apps will slightly slow your puter down on boot up i beta test certian applications bitdefender internet security is another one ....

and i use a quad based pc , but you do notice

_________________
Nikon D90 / 55 - 200 VR / 50 - f1.8 / tammy 90 / SB - 400

I was using AVG Free and it was a PIT*.... dang slow and consuming a lot of resources.
Now I bought an license for PrevX and am truly happy. You can barely notice the thing running and it popped out lots of my Bit Torrent files as being infected. Lucky me

_________________
Canon 40D and lots of lenses.
my Flickr

Oddly, I've found that different AV software impacts different computers - differently.

On some PC's, Norton products have a real nasty slow-down effect on many processes. On others, not so much - and I mean beyond the mere relation to the overall processing power of the PC.

At this point in time, I am using AVG free and I notice no slowdowns on any processes at all. I've tried PC-cilin, NOD32, Norton on this same PC and they all slowed down my dual-core 2GB rig - and this is considering that only the AV part of the software was running - and I'm talking only the AV piece of the software.

I'm not using my scanner much, so I haven't really noticed anything. However, I would think that the AV software should be "smart" enough to realize that the scanner is part of your internal network and that you can't really obtain a virus through the the image-info. Yes, you might be able to get one that has been embedded in the scanner buffer-memory (very exotic). Hence, the AV software shouldn't really have to scan the incoming bit-stream.

however, if your scanner is on a network - i.e. shared with another PC though eitehr a LAN or a USB hub for example - it's possible that the AV software considers the scanner as an external entity.

Perhaps some AV software has an option to specify what sources should be treated how.

Cheers

When I was using Windows, my AV/Firewall programs definitely slowed boot times and caused problems with some of the programs that needed access to the network/internet. However, they never slowed them down, they either worked or didn't.

Recently, I've used Kaspersky, Panda and Norton with Panda being the fastest.

_________________
Graham
Flickr

Slight disclaimer: I work as a software engineer for an antivirus firm (Sophos Plc), so hopefully I can give my two pence worth.

Anti-viruses are always doing something, regardless of whether you've triggered a scan or not. On-access scanning scans each file as it is being opened. That's how these anti-viruses catch threats before they infect you. If it was up to users to trigger scans, users will never get around to it so we always have a background on-access scanner running that's hooked into the filesystem driver. Most on-access scanners have two settings: scan executables or scan all files. If you scan all files, this can dramatically slow down your computer since it literally scans *all* files that are accessed, even stuff that do not usually contain viruses like text files, image files, etc. For most users, scanning only executables is sufficient.

Files within archives like Zips, Tars, Rars, etc are all scanned too by the on access scanner. This requires the zip files to be decompressed to a temporary area and each one is then scanned individually. That's why you notice a long wait before you can access the zip files you download from the internet.

Different virus scanners have different performance characteristics. For home users, I've heard good things about NOD32.

_________________
PhilipGoh.com

That's interesting information pgtips!
But what is the general procedure if a file is just being generated, either by a stream from a scanner, or e.g. by video-editing software that is just (trans-)coding a large video-file.
Will the AV-software work on the incoming stream resp. while the file is being written to the disk or will it normally wait until the file is complete and then start analysing the file? With my scanner I really had the progress bar proceeding slower during the scan with AV-s/w on than off.

----
6 to go...

_________________
Thomas (beware: Nikon-fanboy and moderator!) My Lens Reviews, My Pictures, My Photography Blog
D800+assorted lenses

Just use Mac, don't care about viruses, and nothing will slow you down.

One Apple a day, keeps viruses away

_________________
Canon 40D, 17-40/4 L, B+W UV normal; canon-50/1.4

The Next Big Thing(tm) is to scan for threats before the hit the disc since one increasingly popular vector for malware is websites. Many a time, these don't even write anything to disk so it's important to be able to scan them when they're in transit. For example, at we hook into the TCP/IP driver and scan files as they're being downloaded from the network (internet, LAN, WAN, anything that communicates with your network driver). All this happens before any writing happens to disk.

In your scanner scenario, a few things could be happening. If you've got scan all files selected (most users do for some reason ), it could be scanning the image file as it's being scanned into memory. Or it could be scanned when it's being written to a temporary file on disk.

Most AVs generally try to scan files before they hit the disk since the earlier you get to scan for threats, the less of a threat they become.

_________________
PhilipGoh.com

Do you run Office? Microsoft spreads malware love to the Mac.

Trojans exist on the Mac too. Do you know that the file you're running is really what you think it is? See the RSPlug trojan.

As Mac OS X's market share increases, the malware problem is just set to increase. The biggest threat to computer security is .... users. Get rid of users and you solve the biggest part of the problem. Most Mac OS X users seem to think that they're immune from malware. One day, that's going to bite them in the butt.

Even as a very security conscious individual, I run an AV on my Macbook. After a long day's work, it's easy to make mistakes. An AV scanner just acts as a good safety net.

_________________
PhilipGoh.com

Hi pgtips, believe me, I use Macs (and never something else) since 10 years. I never use antivirus program, and trust me, I NEVER HAD ANY PROBLEMS WITH VIRUSES... There was a time when all my friends, PC users were talking all the time about viruses that I decided to download some, trying to see what are they... no chance... if you have Mac forget about all that Antivirus programs... free up your mind and enjoy the life.

By the way, all that years there were attempts to scare Mac users with mac viruses.... Well, I am 44... already used to that strategy...
A, one more thing- all my friends-the PC users, now have Macs, and don't worry anymore about viruses

Have a peaceful, virusfree Silver night!

_________________
Canon 40D, 17-40/4 L, B+W UV normal; canon-50/1.4

.
Hmm. Reminds me of the comedy sketch where the guy walks into a lamp post because he's too busy looking across the street at an attractive woman. Malware is rare on the Mac platform but if it didn't exist Apple wouldn't be issuing security patches or offering anti-virus software on its site.

A fair summary of Apple's official position is offered on the BBC News page Apple removes anti-virus advice:

"The Mac is designed with built-in technologies that provide protection against malicious software and security threats right out of the box," an Apple spokesman said.

What the Apple spokesman fails to consider is the idiot factor where we, yes - Windows users as well, unintentionally install malware. There is also the situation where an "essential" third party utility, such as Flash, turns out to have security holes that need fixing. Security software can help by providing a layer of detection and warning that something's amiss during that critical period between Apple verifying a security flaw and issuing an update.

Bob.

_________________
OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.