S L O W site loading speed problem

I am having loading speed issues with 2 sites of mine. I have done tests on webpagetest.org with very concerning results.

Both sites are on the same server at GoneDaddy in the U.S., both have "first byte"times in excess of 5 seconds and Document and Total Upload times in excess of 11 seconds (as high as 17 seconds). So maybe it isn't either of the P's afterall that is affecting my SERPs.

Aside from the obvious failure of First Byte the major failure from the test is "Leverage browser caching of static assets: 18/100". (There are also some less than impressive scores for Combine static CSS and JS files: and Use a CDN for all static assets: ) but it is Caching of Static Assets that apparently is the killer.

The two sites in question are both ZenCart eCommerce sites

Q.1 What is Caching of Static Assets and where/how can it be controlled such that it doesn't adversely affect site loading speed. How can I rectify this situation?
Q.2 What could be causing the problem. In the test results I notices certain images took a long time to load (800-3600ms) and many of the images were specific to Ultimate Fade-in Slideshow which I have on the home page of both sites (code is in define_main_page via admin tools control). I deleted the code but got a div error message - fadeshow1 cannot be found - after clicking the ok box I did another test (without fadeshow) and there was no difference.

As you can no doubt tell this is most disconcerting - rankings and sales continue to fall.

Sites are jewelleryonlinestore.com.au and harmonyballpendants.com

Looking forward to some assistance.

cheers,
Shags

p.s. other sites on the same hosting account/server that are not Zencart/eCommerce do not have the First Byte issue and have good site loading speeds albeit all have the same FAIL mark for Caching of Static Assets. Hence the First Byte issue likely rests with a ZenCart code error.

Addressing your points in reverse order, because this order is more important:

2. Your server.
   GoDaddy's biggest problem is that their database servers aren't tuned to give quick response, so your Zen Cart store sits waiting for the database to catch up. Hence your "first byte" problem.

So, yes, it most likely is your host.

If you took that same store and moved it to someplace like GeekHost for example, your "first byte" problem would disappear instantly.
And then your "cached assets" issue would be almost moot too.

1. Cached assets
   You could try the following concept to improve caching of page assets:
   http://www.zen-cart.com/content.php?320-Speed-up-site-by-caching-page-assets

I can't answer the technical questions, but i can offer a couple of possible reasons for your sites' slowness.

Your product images are way too big (file size, not dimensions). You're trying to load almost 1Mb of imagery on the main page. Product images (the smallest version) should be optimized to less than 10Kb each.

Your host. You yourself call them GoneDaddy, and they're notorious for overloading their servers. Your other sites on the same server (if indeed they are - it's hard to know for sure with GD) may not be database driven, which may mean the bottleneck is in GD's database configuration (or, again, overloading). My guess is you'll continue to have problems until you find a quality host.

You only have some minor validation errors, but it wouldn't hurt to fix them to remove that from the equation. They're mostly unescaped ampersands and missing alt tags.

Edit: What DrByte said.

More tips:
http://www.zen-cart.com/content.php?63-how-do-i-speed-up-my-site
http://www.zen-cart.com/content.php?43-performance-tuning

DrByte:

Addressing your points in reverse order, because this order is more important:

2. Your server.
   GoDaddy's biggest problem is that their database servers aren't tuned to give quick response, so your Zen Cart store sits waiting for the database to catch up. Hence your "first byte" problem.

So, yes, it most likely is your host.

If you took that same store and moved it to someplace like GeekHost for example, your "first byte" problem would disappear instantly.
And then your "cached assets" issue would be almost moot too.

1. Cached assets
   You could try the following concept to improve caching of page assets:
   http://www.zen-cart.com/content.php?320-Speed-up-site-by-caching-page-assets

How can you leverage browser caching? And set expiration date for images?

GTMetrix says "expiration not specified"!

It also says that image dimensions are missing, but it displays the dimensions on the report.

Has anyone encountered that?