Is Drupal 7 slower than Drupal 6?

One of the problems with Drupal in general is that it is slow. We run Pressflow 6 in a high traffic production environment and it consumes a lot of resources for a site of its size.

Much has been made of whether Drupal 7 is slower than Drupal 6:

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It appears that this **is** indeed the case, but can anybody confirm?

Many thanks,
Chris.

Depends.

Yes, out of the box, D7 is slower than D6. But a lot of effort has been put into making it *scale* (Which is a different thing than being performant).

Many of these features are actually already part of Pressflow 6 like support for master/slave database cluster, proxy, improvements to alias handling and so on. So that doesn't help you much.

But there are also features which did not exist there, for example the pluggable field storage that allows you to store all your fields in MongoDB for example. Also, while D7 in general is slower, the queries have been improved a lot and the bottleneck basically moved from the database to PHP, which is easier to cluster.

After all, D7 is able to power sites like

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:) And they explicitly chose D7 over D6 for scalability improvements like MongoDB integration.

Yes. I can confirm. However.

First the bad news:

* Drupal7 core is more complex. Complexity costs performance.
* Drupal7 core is bigger: more features, more in core. **more** equals **slower**.

Then the theory:

* In Drupal6, approx. 95% of the projects included CCK. Call that Drupal+. Drupal7 comes with CCK out of the box. Drupal6+ is **slower** then Drupal7.
* Drupal7 offers a lot of enterpris-ish abilities for performance tuning. Memcached, (Varnished)Proxy support, Database balancing (master/slave etc). Something that Drupal6 could not do.

However, [Drupal6 pressflow had these enterprise-ish things build](

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) in (in fact: these pressflow features made it into core, offering the basis for Drupal7).

[Drupal7 is slower then Pressflow Drupal6](

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). Drupal7 offers performance features that Drupal6 did not offer, but that PressflowDrupal6 did offer.

Many projects also have views module enabled. Views3 in Drupal7 offer a lot of performance improvements (enterprise-ish features) over Views2 for Drupal6.

My advice: untill there is a performance-optimised Drupal7 (Pressflow Drupal7, for example) Just stay with your Pressflow Drupal 6. It is in both theory and practice a lot faster.
If you can benefit from the Views3 improvements and features, then go for Drupal7+views3, that will give you more options to tune performanceissues.

I think it is hard to tell which one is faster or slower. Drupal 7 just see everything as entity. But one thing I notice by drupal profiling

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is Drupal 7 panel is extremely slow. So I suggest we always go with templates.