The reason for slower http download with Avast 10.4.2233 compared with 10.2.2215

Avast Free Antivirus / Premium Security
1

The ironically named ‘intelligent stream scanning’ is the cause of much reduced http download speeds with Avast 10.4.2233 when running on Windows XP. Avast 10.2.2215 is not adversely affected by enabling ‘intelligent stream scanning’ but Avast 10.4.2233 is. Switch it off and speed goes up considerably and the CPU appetite by AvastSvc.exe diminishes greatly but you have to start a new download to realise that.

Anyone like to suggest why this is so? The behaviour is not apparent with Windows 7 and I guess that Avast 10.4.2233 was designed with Windows Vista/7/8/8.1 and later in mind.

I have not properly evaluated this issue and not yet sure that updating Avast 10.2.2215 to 10.4.2233 will not cause me to regret doing so in pursuit of the benefits of https scanning.

2

Where is that setting ?
The reason I ask is I can’t see it on my XP Pro SP3 system using avast 11.1.2245, so it may have been removed for XP systems.

Which would then beg the question, why aren’t you using avast 2016 ?

3

The relevant screen shot from Avast 10.4.2233 is attached.

My poor old AMD Athlon XP 3000+ processor is pre-SSE2. Avast 10 will run but Avast 11 won’t. I’ve got loads of useful old stuff on the system which is trapped because of the HAL. This desktop PC is only 14 years old and therefore still in adolescence.

4

I reckon he means the one located in the web shield settings right underneath the enable https scanning . I have not noticed any difference whatsoever regarding download speeds. I’ll check it again and report shortly. Cheers

5

Well, no difference at all in my system. CPU consumption and download speed seem to be very similar indeed.

Cheers

6

hake,

there is no reason to start a new thread about the same and pollute this webboard.

https://forum.avast.com/index.php?topic=182085.msg1286456#msg1286456

7

A shame that as the ‘Use intelligent stream scanning’ option isn’t present in XP on 11.1.2245.

8

I was trying to develop a useful discussion. I wanted to communicate my observations to others in the belief that they would find them of interest. I apologise for polluting the forum.

I have installed Avast 10.4.2233 on my Windows XP pre-SSE2 CPU equipped PC and it works great with Web Shield ‘intelligent stream scanning’ switched off. I noticed that the Update Settings do not mention updating to Avast 11.1.2245. That must mean that my pre-SSE2 processor is recognised as not compatible with Avast 2016. One up to Avast! I wish that other firms were so thoughtful. Avast seems to think things through.

However, it is quite confusing to find that ‘intelligent stream scanning’ creates a performance hit with at least some Windows XP systems.

9

???

Today I made another attempt to use Avast Free 10.4.2233 on my antiquated non-SSE2 Athlon XP 3000+ powered Windows XP SP3 PC and it now works great. Https scanning now works without affecting download speeds and the general behaviour of Avast 10.4.2233 is impeccable.

I have previously noticed other apparently unaccountable aberrant software behaviour. Glitches obviously come and go in Windows.